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AstroFan: It’s a star! It’s a planet! No—it’s a brown dwarf?!

Image Credit: NASA/JPL-Caltech

Our Universe is filled with strange objects that even scientists have trouble classifying. Read on to learn about brown dwarfs, the celestial objects that are kind of like a star and kind of like a planet but are actually neither.


A wise man once said, “Only a Sith deals in absolutes”.

That wise man was a jedi-master named Obi-Wan Kenobi, and he said those words during the climactic battle on planet Mustafar in (arguably) one of the greatest episodes of Star WarsRevenge of the Sith.

In the case of brown dwarfs, most astronomers would agree with master Obi-Wan. For today’s topic, it is most salient that we stray far, far away from speaking in absolutes.

You see, brown dwarfs are very wonky in that they are neither a star nor a planet—they’re sort of something else entirely.

The life of a brown dwarf starts off similar to a star; both form from a collapsing cloud of gas and dust. The difference here is that once brown dwarfs form, they lack the mass that is needed to support nuclear fusion.

Nuclear fusion is when low mass atomic nuclei are built up into higher mass atomic nuclei in a star’s core, releasing energy and fueling the star in the process.

Since brown dwarfs don’t have nuclear fusion they behave differently than a star and are essentially massive objects composed of gas and dust with no fuel to burn. Brown dwarfs are less massive than the Sun but much more massive than gas giants (i.e. 13 to 90 times more massive than Jupiter).

Image Credit: Carnegie Institution for Science

When a brown dwarf first forms, it starts out being pretty hot due to the physical forces that made it, but without nuclear fusion, brown dwarfs inevitably cool as they age. Higher mass brown dwarfs cool a lot more slowly and have a higher luminosity for a longer period of time than lower mass brown dwarfs. Most brown dwarfs glow in the red and infrared spectrum of light.

A fun fact about brown dwarfs is that shortly after they were first predicted in the 1960s, scientists thought that their existence could explain the mysterious case of dark matter. (For those who don’t know, dark matter is a material that is unobservable to scientists and is believed to make up 80% of the mass in the Universe.) It later turned out that brown dwarfs were nowhere near numerous enough to be an important component of dark matter!

Although the existence of brown dwarfs didn’t explain the mysteries of dark matter, it has been suggested by some that brown dwarfs could offer another way for life to thrive in our Universe.

Recently, researchers at Harvard University proposed that the upper-atmosphere of some brown dwarfs may have habitable conditions for life. We’re talking a microbial oasis of water vapor, warm temperatures, and nutrients. Think about thatlife thriving in the clouds of these non-planets!

Speaking of atmospheres, when it comes to brown dwarfs, things get… interesting. Unlike the atmospheres of stars, brown dwarfs have atmospheric winds that fall into regular belts and zones.

Due to their higher masses, it has been hypothesized that the storms that occur on brown dwarfs are larger and more powerful than the ones typically seen on the gas giants in our Solar System.

An artist’s rendition of what a storm on a brown dwarf could look like.
Image Credit: NASA/Cal-tech

As you can see, brown dwarfs fall into a league of their own. Their very existence has helped astronomers begin to bridge the gap between gas giants and stars.

Brown dwarfs prove that sometimes it is very difficult to group celestial objects into neatly delineated categories. They prove that sometimes the natural world creates objects that have such unique characteristics that they completely change the way astronomical objects are categorized.

So, if you’re ever at a dinner party and hear someone say “ A brown dwarf IS a star” or “A brown dwarf IS a planet,” remember the wise words of Obi-Wan Kenobi…

Stay tuned for more awesome space facts on the next AstroFan.

Thank you for reading!

—Bianca, a.k.a. AstroFan

Adler Staff Star: Pride Month!

For this month’s Adler Staff Star we decided to highlight the employees at the Adler who embody what it means to be an ally and a part of the LGBTQIA+ community.


What does Pride Month mean to you?

“Pride Month is a remembrance/memorial for the brave trans-women of color who fought for visibility and equality at stonewall, a continuation of work worldwide, a celebration of how far the queer community has progressed, and an acknowledgement of how far we still have to go. This Pride Month, I will be working especially hard to be a good ally to my trans-siblings in the community, especially to trans-people of color.” – Jordan Scherer

“For me it is a time of celebration and remembrance. A celebration that encourages myself and the whole community to be who they are without apologies or mandates. Remembering those who have paved the way for the lives that we all lead now. Pride has always given me comfort and when I attended my first Pride 15 years ago it showed me that I wasn’t alone, even though many in the community sometimes feel like they are.” – Josh Stewart

What part of the Adler’s Pride Month celebrations are you most excited about?

“I love the shirts and the buttons. I am very excited for Adler After Dark: Out in Space. The panel sounds awesome and it’s just amazing to me to have an organization like the Adler showcase members of the LGBTQIA+ community and stand behind Pride.” – Joseph Wesolowski

“Out of all the events the Adler is doing to support and welcome the LGBTQIA+ community, I think changing the Grainger Sky Theater to multi-colors is what I’m most excited about. I work mostly at the main box office so it’s nice getting to see lively colors for a change while I’m here for shifts.” – Daniel Noriega

“I love being able to look out the window and see a very inclusive Pride flag waving in the wind.” – Martha Garcia

In your opinion, how can heterosexual and/or cisgender people work toward being good allies to the LGBTQIA+ community?

“I would say; just listen, be humble, and stay open to new and sometimes uncomfortable ideas. Learn about our cultures, see a drag show, talk to a trans-person or someone living with HIV. And by all means, have fun! Just don’t make it about you. One of the discouraging movements I’ve noticed a lot more this year is a push for a “Straight Pride” counterpoint. This misses the point. Pride is a moment for those of us who have been invisible, excluded, ignored, and mistreated our whole lives. This is our counterpoint to a whole world designed for straight and cis-people.” – Jonathan Russell

“Understand that 90% of being an ally is listening, the other 10% is using your privilege to speak up if and when unjust situations arise.” – Jasmine Porter

“Continuing to be more proactive about inclusion and pronouns.” – Kira Mangum

Share one interesting fact about yourself!

“I’m working on a pseudo-fantasy epic about mostly queer characters! My worldbuilding style is deliberately queer as well.” – Jonathan Russell

“I am an identical twin. He is my best friend and we go to the Twins Days Festival every year!” – Josh Stewart

Meet “Out in Space” Panelist: Bryan Terrazas

Meet Dr. Bryan A. Terrazas, NSF Fellow and Rackham Merit Fellow in the Department of Astronomy at the University of Michigan, at Adler After Dark: Out in Space! Dr. Terrazas will be featured in a panel discussion about the importance of having a broad range of perspectives in the scientific community.

Meet Bryan at Adler After Dark: Out in Space!
Dr. Bryan A. Terrazas

Why have you chosen to pursue astrophysics as a career?

My interest in astrophysics stems from the fact that it deals with things that we as humans cannot touch, move, or manipulate. The objects we study in space are incredibly far away, enormous in size, and operate at timescales of millions to billions of years. Their existence is completely different from what we experience in our day-to-day lives. Because of this, instead of being hands-on experimentalists, astrophysicists are mostly observers and interpreters. We live on a planet revolving around one of billions of stars in our galaxy which is one of billions of galaxies in our universe. Yet we’ve developed methods for understanding the universe through mathematics and the scientific process that give us remarkable insights into the way things operate in space.

It takes persistence and, most importantly, a lot of creativity to tease out information about the universe from our limited human perspective. Figuring out creative solutions to the universe’s biggest unsolved mysteries is detective work that requires piecing together evidence and writing down a consistent story for how things work. This is a difficult but incredibly rewarding task. I find it very exciting to devote my career to expanding our knowledge about the universe.

Can you tell us a little bit about your research and work on galaxies?

I care about how galaxies have grown and evolved throughout the history of the universe. More specifically, I want to know why some galaxies are actively forming new stars, while others are not. Star formation is one major way a galaxy grows, so it’s concerning when a large number of galaxies have stopped the majority of their star formation. There are many ideas for what could lower the rate of star formation, but the most popular theory today has to do with the supermassive black hole that resides at the center of most if not all galaxies. My work focuses on the connection between these central supermassive black holes and the amount of star formation in their host galaxies.

Specifically, my collaborators and I have shown that galaxies with more massive black holes have suppressed star formation activity to a greater extent than those with less massive black holes. However, a coherent picture of how this process works in galaxies has yet to be discovered. In September, I’ll be starting a postdoctoral fellowship at the Center for Astrophysics at Harvard & Smithsonian where I’ll be gathering more evidence and trying to piece together a complete narrative for how black holes affect galaxies.

While at the University of Michigan, you led the effort for the creation of the Committee on Equity and Inclusion within the Astronomy Department. What motivated you to do this?

The motivation came from the 2015 National Society of Black Physicists Conference in Baltimore, MD. Together with my close friend and fellow graduate student at the time, Alejo, we came up with the idea after many discussions on how we could improve recruitment and climate for black and brown scientists. We had proposed the idea of sending representatives from the University of Michigan to the meeting and we decided that we would go a step further by proposing an official committee. We felt the need to do this because, through those conversations, we had identified several specific areas where the department could improve through more direct and concrete actions. Profs. Emily Rauscher and Nuria Calvet, who were also in attendance at the meeting, said they would provide full support and help present a case to the department through a formal presentation. We were successful, and the committee began its work a few months later during the 2015 Fall semester.

What was the vision and goal of the committee?

We envisioned the committee as an institutionally-recognized group of department members from all levels who would actively think about how to make the astronomy department a safe and welcoming space in which anybody could do science. Academia is predominantly made up of people who are white, male, cisnormative, heteronormative, non-disabled, and wealthy. In order to make the department welcoming for all, particular effort needed to be aimed at ensuring that people who do not fit into those demographics were being actively recruited to the program and supported throughout their time here. This last point is important: it was vital that the committee have the power to address issues regarding climate in order to ensure that those who were being recruited would feel safe and supported as they build their careers.

Since 2015, what changes have you noticed in the department as a result of the committee?

Since its inception, the committee has done a lot for the department. In terms of graduate admissions and recruitment for the next generation of astrophysics PhDs, they have organized recruitment efforts and attendance at meetings for underrepresented folks in science (e.g., NSBP, SACNAS), eliminated the physics GRE requirement, and introduced methods for avoiding bias when assessing applications. Additionally, they have organized a bimonthly event for the discussion of various social issues present in the scientific community, introduced gender-neutral signage for departmental restrooms, and centralized clear and transparent guidelines for dealing with issues of harassment. Change is slow and often frustrating when going against the status quo that everybody is used to, but it’s wonderful to reflect back and be able to concretely list these successful outcomes after four years. A lot more work needs to be done, but the committee has been a great first step forward.

When did you first become passionate about improving the climate for underrepresented minorities in astronomy and the broader STEM community? What sparked the desire to be someone who advocates on behalf of others?

Coming into my PhD program, I was in the extreme minority as a queer Latinx graduate student and first generation both in terms of attending university but also as a US citizen. Academia caters to a specific demographic and socio-economic status that often creates a hostile environment for people who don’t fit that mold. What’s worse is that it often goes unnoticed by people who do fit that mold. Throughout my PhD program I had moments of questioning whether it was worth dealing with each microaggression as it came up and constantly having to defend the importance of equity and inclusion issues to people in power who didn’t have a clue what it meant to be someone like me in that space. All this feeds and adds a layer to the impostor syndrome that affects many underrepresented people in science.

Every time I felt that way, I knew I wanted to work with similarly-minded people to change that culture. I wasn’t the only person with these feelings and that gave me the impetus to reach out and start organizing with people. Some of the most influential of those were Chanda Prescod-Weinstein, Jedidah Isler, and Jorge Moreno who have all been incredibly influential to me with regards to the way in which I engage with these issues and also the way I balance my science work with my advocacy work. The community of scientists who care about these issues have done a tremendous amount of work to ensure the survival of bright, young scientists who would otherwise likely be discouraged from pursuing science. My hope is that in the future the conversation will shift to focus not on how we can survive but rather how we can thrive.

In your opinion, why is it important to have LGBTQIA+ representation in the scientific community?

LGBTQIA+ scientists are often invisible. Work discussions don’t center around that aspect of people’s identity, particularly in astronomy where we talk about stars and galaxies but not so much about gender expression or identity, for instance. Yet, heteronormative and cisnormative culture and expression are everywhere in the scientific community. Having spoken to other queer scientists, I realized that often there was an internalized tendency to assimilate into this world of professional cis-hetero-normativity. This is a big problem. Having openly queer folks in science changes the common perception of what a scientist is and what they should look like. I also want to note that this is absolutely an intersectional issue. It’s critical that movements that seek to advocate for LGBTQIA+ people also do so for black and brown people, people with disabilities, people with lower socio-economic backgrounds, women, and people who are any combination of these identities.

If you could snap your fingers and change one thing about the scientific community as a whole, what would it be?

If I could only choose one thing, it’d be dismantling the top-down hierarchies of power in academia and building new power structures that are more equitable and inclusive.

In my experience, top-down hierarchical power structures enable imbalances in determining who is heard and what action is taken. When this is the case, a few people can make decisions that affect groups of people who have little to no say and who are likely not represented in the decision-making process. This can be devastating for people with less power who need to find support against climate issues ranging from microaggressions, sexual or gender harassment, abuses of power, or any other problems that may arise. There are people in power who have used their positions to advocate for those who need support but this is generally insufficient and unsustainable. If the scientific community wants to become a more inclusive and welcoming space, there needs to be institutional structures in place that allow power to be distributed equitably across all members of the community. This is far from the only change that needs to be made, but I believe that by redistributing power, more voices will be heard and a first step can be taken towards improving the climate in the scientific community.


Want to get to know more about Bryan? Follow him online!

Website: bryanterrazas.weebly.com
Twitter: @bryan_terrazas

Looking Up and Reaching Out

“One of the things I’m passionate about is bridging the culture wars,” Adler Astronomer Dr. Grace Wolf-Chase says cheerfully.

In her office, Grace is rifling through a stack of bright pink foam-board posters featuring portraits of religious people who’ve made great contributions to science. She separates one from the rest. The bearded face on it belongs to Brother Guy Consolmagno, the director of the Vatican Observatory. “And,” Grace adds, grinning, “winner of the Carl Sagan Medal for public communication of science.”

She pulls another poster from the stack: A 19th-century Jesuit priest named Fr. Angelo Secchi.

“And then there’s this fellow here. This was the first person to study the spectra of stars by passing them through a spectroscope, thus turning the science of astronomy into astrophysics, essentially.”

Grace has been a research astronomer at the Adler for more than 20 years. She’s also a prolific writer on space science for religious leaders, a science advisor to three different local seminaries, and a member of several organizations that explore the intersection of science and religion.

Her affection for faith communities—and theirs for her—may seem unusual in a time when so much of the cultural conversation is a loud argument about who belongs where, who is “us,” and who is “them.” There is a pervasive—and, Grace says, ahistorical and wrongheaded—idea that science is a threat to religious people and that serious scientists can’t possibly be religious.

Grace has a lot of practice seeming unusual to others. As a child, she was captivated by the Apollo missions and the promise of other worlds. In a time when traditional gender roles were enforced even more strictly than they are today, Grace was a girl who excelled in math and science, a competitive figure skater who loved Star Trek, and a shy kid who might be quietly developing a plan to jump out of a tree with a homemade parachute. She owned both an Easy Bake Oven and a chemistry set, and she would often combine their powers to fascinating (and probably dangerous) effect. Later, as an undergraduate at Cornell University, she recalls being one of only two women in the entire physics program.

Semi-permanent outsider status has its perks. One is the opportunity to be a human bridge between groups of people who don’t fully understand each other, to show them what they have in common. Today, Grace is a religious scientist who studies the formation of stars and draws on her eclectic personal history to make room in astronomy for people who might feel out of place—especially people of faith.

“There are a number of people in religious communities that see communities of science as a chilly climate for them in the same way that somebody from a different culture or a young girl would,” she says. And allowing them to keep thinking there’s no place for them in science would have the same devastating effect as excluding people because of their race or gender: Countless wonders would go undiscovered, problems unsolved, minds unmet.

Adler astronomer Grace Wolf-Chase speaks to an audience of students and the public at McCormick Theological Seminary in February 2019. Credit: Tricia Koning Photography.

“There are truly brilliant scientific minds who are also people of deep religious faith, and they live comfortably with these two sides of themselves,” says Grace. “They see what they do in science as a form of worship.”

Grace sees it that way, too. When she studies images of a previously unknown stage in the life of a star, it’s a religious experience. When she reads a psalm, she thinks about the glittering night sky that would have enraptured its author.

“That awe and wonder is not muted by deepening our knowledge of the cosmos,” she says. “It’s enriched. It makes the whole story just that much richer and grander and more inspiring.”

How Many People Does it Take to Discover a Planet?

The evening of March 13, 1781, William Herschel was observing the sky with a fine 7-foot refracting telescope he’d made by himself, from the backyard of his home in Bath, England. At that time, Herschel was earning his bread as a musician, but he had been developing a strong interest in astronomy, sacrificing many of his rest hours in order to devour books on the subject and build telescopes.

Detail of an orrery (mechanical model of the Solar System) originally built c. 1740 by Thomas Heath in London, England, and later expanded to include Uranus. Note that Uranus appears with the name originally given by Herschel, Georgium Sidus.

While probing the area around the star Zeta in the constellation of Taurus, Herschel noticed the presence of an unusual star. Stars should in theory appear as points of light when seen through a telescope, but this one seemed to have a visible size. What Herschel had stumbled upon was no less than the planet Uranus. While Mercury, Venus, Mars, Jupiter, and Saturn can be seen with the unaided eye (provided they are above the horizon, the sky is clear, and observers know where to look), Uranus will normally require a telescope to discern it among the stars. Herschel thus became the first person to discover a planet since antiquity.

At least, this is a nice way of telling the story, even if overly simplistic. First and foremost, how did Herschel himself react to what he saw through his telescope? To begin, it was necessary to check if the object was moving against the starry background. Herschel was able to confirm that just four days later, with new observations. Still, he did not promptly assume that the moving object was a planet. In fact, he initially described it as being either a “nebulous star” or a comet, leaning toward the latter.

Herschel had been establishing good relations among the English scientific community of his time, and did not take long to share the news about the unusual object with other astronomers. However, at the time Herschel was just an amateur astronomer getting started, and his lack of experience showed.

Not that there were that many astronomers by then who would qualify as professionals, but Thomas Hornsby at Oxford and the Astronomer Royal Nevil Maskelyne at Greenwich were certainly part of that select group. The two seasoned astronomers immediately asked for the coordinates of the object, in order to keep track of it themselves. But Herschel could only provide an approximate description of its observed positions in the sky.

Portrait of William Herschel by Frederick Rehberg, 1814. The background shows the area of the sky where Uranus was located when Herschel first observed it. Original print in the Adler’s collections.

It is true that it was Herschel who started the process that led to its identification as a planet. But as shown above, its discovery was much less a sudden, momentous feat of one individual than a gradual process involving several other people.

Besides, the anomalous appearance of the object was more evident through Herschel’s own telescope, which further contributed to Hornsby and Maskelyne (especially the former) taking pains before they could finally track it down after weeks searching. Hornsby initially supported the idea that it was a comet, whereas Maskelyne posited it was either a comet or a planet. It was only by the summer of 1781 that, using precise observations amassed by these and other experienced astronomers, mathematicians were able to compute the orbit of the object and confirm that it was, in fact, a planet.

Following the advice of Joseph Banks, one of the leading figures of British science at the time, Herschel named the new planet Georgium Sidus as homage to King George III, which granted him the king’s patronage and allowed Herschel to concentrate on astronomy and telescope making for the rest of his life. In continental Europe, and especially France, the planet was known as Herschel before it was finally christened Uranus, following the old tradition of naming planets after the gods of classic mythology.

Herschel first spotted what came to be recognized as planet Uranus using a telescope very similar to this one in our collections, which was also made by him.

Interestingly, Uranus had already been included in star catalogs before Herschel observed it, but just as another star. It is true that it was Herschel who started the process that led to its identification as a planet. But as shown above, its discovery was much less a sudden, momentous feat of one individual than a gradual process involving several other people. We may continue to celebrate Herschel as the first person to ever discover a planet since antiquity, but we should not forget that the discovery was not only his. This caveat applies to whatever scientific discovery, astronomical or otherwise, we may choose to focus on.

What we call scientific discovery is usually a process that unfolds in time, not a single “Eureka!” moment, and the “discoverer” is almost always a group of people, regardless of who started or led the process, or who was better or luckier at getting credit for it.

Imagining the Moon

You probably know that it takes many minds and lots of teamwork to achieve scientific breakthroughs like human spaceflight. But did you know the same principle applies to complex terrestrial feats like producing a planetarium show?

The Adler’s newest show, Imagine the Moon, was a massive team effort. The Adler’s Guest Experience and Theaters teams worked together to develop an engaging story, staff members within our Astronomy and Collections teams selected exciting themes to explore, and our Visualization team brought everything to life on the dome. Executing this collective vision was only possible at a place like the Adler, where experts in diverse fields work together every day to connect people to our Universe.

Imagine the Moon explores how the Moon has inspired human creativity, learning, and exploration ever since people looked to the sky. People all over the world have imagined the Moon in different ways: As a faraway apparition, a glowing disk in the sky, a destination in space, and a world that shares its origin with Earth. As we celebrate five decades since the Apollo missions brought astronauts to the Moon, Imagine the Moon reveals how the Moon has been a source of wonder for all of human history.

Four hundred years ago, when Galileo pointed telescopes at the Moon, he saw mountains and craters instead of a perfectly smooth surface. The Moon became a world that people imagined they could visit. For Imagine the Moon, the Adler’s Collections team identified books in our collection containing new ideas for traveling to the Moon. One 18th-century author imagined a vessel like a small boat that included a telescope for making observations, flapping wings for gaining altitude, and a cannon for keeping possible lunar residents at bay. Thanks to a new animation developed by Adler’s visualization team, Imagine the Moon shows what this fanciful vision might look like in real life.

Visions of going to the Moon led to real journeys of discovery. Humans traveled to another world during the Apollo missions. The global population came together to witness these events in a way that had never happened before. Imagine the Moon shows perhaps the most surprising perspectives shared by these intrepid explorers (and given new life by our visualization team): Views of planet Earth as a small island in space.

Imagination is an essential part of expanding our knowledge and understanding. Moon rocks returned by the Apollo astronauts provided clues that the Moon likely originated billions of years ago from a massive collision between the early Earth and another body. The Moon continues today to spark the imagination of scientists. Using scientific imagination and cutting edge research, Adler astronomers worked with colleagues to visualize a new theory that expands on ideas about how the Moon formed. This new theory suggests an early collision with so much energy that it vaporized much of the two objects and forming both Earth and Moon. Imagine the Moon presents this theory in a breathtaking visualization for the first time in a planetarium show.

People all over the world see the same Moon in the sky, and the Moon has many more mysteries yet to be solved. By bringing together diverse perspectives to produce Imagine the Moon, the Adler invites everyone to feel a connection to the sky and imagine the Moon for themselves.

Adler Skywatch: June 2019

The longest days and shortest nights of the year—for Earth’s Northern Hemisphere, anyway—take place this month, June 2019.

The first day of summer for the Northern Hemisphere occurs on the solstice, at 10:54 am CDT on the 21st. It’s the longest day of the year, with the Sun rising very early and setting very late. In Earth’s Southern Hemisphere, it’s just the opposite: the Sun rises late and sets early—and it’s the first day of winter. The fact that the hemispheres celebrate opposing seasons points to its cause: the slight tilt of Earth’s axis directs more solar energy to the half of the globe leaning toward the Sun.

Once the Sun sets this month, try spotting some planets in the darkening sky. If you have a clear view to the west-northwest horizon, the planet Mercury may be visible about a half-hour after sunset—but it’s only about ten degrees above the horizon. The evening of the 4th, it’s the brightest star-like object to the right of a very slim waxing crescent Moon—which itself may be hard to see, being less than two days past New Moon. The evenings of the 16th through 19th, Mercury appears within a degree of the planet Mars. Mercury is the brighter of the two planets this month. As June draws to a close, both Mercury and Mars get dimmer and lower in the sky; by month’s end, they both become very difficult if not impossible to spot.

Later in the evening, look for the bright planet Jupiter low in the southeast. It appears about ten degrees to the left of the reddish-colored star Antares, in the constellation Scorpius. Jupiter is by far the brighter of the two. Start looking for Jupiter around 11:00 pm CDT at the start of the month, and about 10:00 pm later in the month. The night of the 16th, it’s a few degrees away from the nearly Full Moon. Shortly after midnight, it reaches its highest point in the sky, only about 20 degrees above the southern horizon. Jupiter sets during morning twilight in the south-southwest. Though it appears close to the constellation Scorpius, technically Jupiter spends this month in the constellation Ophiuchus—which is sometimes called the 13th Zodiac constellation. Like the traditional twelve Zodiac constellations, Ophiuchus lies on the ecliptic—the Sun’s apparent path in the sky—between Scorpius to its right, and the constellation Sagittarius to its left.

Shortly after midnight this month, look about 30 degrees to the left of Jupiter, to find the planet Saturn. In the early morning darkness of the 19th, it’s only a degree away from a waning gibbous Moon. Saturn fades from view in the south-southeastern sky during morning twilight.

If you have a clear view toward the east-northeast horizon, try spotting the planet Venus about 4:45 am CDT. It’s very low, but very bright. The Sun rises in the Chicago area around 5:15 am CDT this month, so once its edge gets close the horizon line, around 5:00 am—stop looking, because looking directly at the Sun can cause permanent eye damage.

New Moon: June 3rd
First Quarter Moon: June 10th
Full Moon: June 17th
Last Quarter Moon: June 25th

Note: these descriptions are for the Chicago area, using Central time.

The tale of an Adler Planetarium family: It’s not (all) about the kids

We’ve been an Adler family since our son, Hudson, picked up his first toy space shuttle and never put it down. I remember his first trip—when he was perhaps three years old—and the look of wonder on his face as it dawned on him that the rockets, the planets, the stars, and moon were all real things, not just pictures in a book. From that day, he’s been devoted to understanding them all more fully.

The toy that started it all in 2012
Hudson holding the rocket that started it all back in 2012.

We’ve been members ever since. Even though we now live near Joliet, we always make it to the Adler several times a year. The membership perks make it easy to line up the whole day’s itinerary right when you walk in since it includes complimentary tickets to the sky shows and other experiences. It’s a great way to structure the day’s visit, and you always have something exciting to move on to next.

Now that he’s nine, Hudson has no problem sharing his favorite stops along the way. I asked him to tell me how he’d like to spend his next visit; the whole list wouldn’t fit here but here are the highlights.

1. Mission Moon and the James Lovell exhibit are at the top of the list. Captain Lovell’s life story really brings his accomplishments, and those of the entire Moon program, down to a relatable level. It makes a career in space exploration seem truly achievable when you learn that your hero grew up with the same dreams you have.

Hudsons hero is Capt James Lovell
Hudson’s hero is Capt. James Lovell, Jr.

2. The pop-up science stations are always a hit, particularly the make-your-own-paper stomp rocket projects. Hudson’s proudest moment was lodging one of them on a hard-to-hit ledge in the Our Solar System exhibit. Kudos to the Adler volunteers who have to retrieve all these “accomplishments” at the end of the day!

3. In a testament to his personal history with the Planetarium, he still loves to visit the Planet Explorers area, build towers of foam blocks and knock them down in slow motion with the X-Mover. Destination Solar System keeps him on the edge of his seat every time, too.

4. Pretty much everything on the lower level is a must-see, now that he’s overcome his fear of the teeth-rattling “big bang” presentation in The Universe: A Walk through Space and Time.

Hudson conquering fear of the Big Bang in 2018.
Hudson conquering his fear of the Big Bang in 2018.

My wife, Tawnie, also loves rediscovering the place she knew as a kid herself. She tells me that old favorites, seen through our son’s eyes, bring a fresh thrill about the Universe and our place in it. For my part, I love digging into the more advanced science and history of sky exploration. Being members of the Adler means that we can return as often as we like to get a fresh dose of wonder.

We’re an Adler family, and will be for a very long time to come.

AstroFan: COSMIC VOIDS!

Header Image Photo Credit: Mark Subbarao, Dinoj Surendran, and Randy Landsberg

Hello! Welcome to our 4th AstroFan! The past few features have dealt with some of the coolest objects in space (neutron stars, our Moon, exoplanets, etc)—this feature of AstroFan is going to switch things up and focus on the actual SPACE around these objects, specifically voids! Read on to learn about this strange feature of our Universe.


14 billion years ago there was nothing, and then BAM—an unfathomably calassol expansion took place, known as the Big Bang. Our Universe went from a singularity (an infinitely small point) to the massive cosmic vista that we see today, and all in the blink of a cosmic eye.

The remnants of the Big Bang can be actively observed in our current Universe.

For one, the Universe has not stopped expanding since the Big Bang. That’s right, space-time itself is continuously being stretched and propelled outward, taking stars, solar systems, and galaxies along with it.  

When viewed on a large scale, the intricately woven structure of our expanding Universe begins to come to life.

On this scale, we can observe large clusters of galaxies forming filaments (200 to 400 million light years in size) that connect to one another.

Between these filaments lurks a reminder of our primordial Universe: cosmic voids.

In the picture above we see a mapping of the cosmic web. Notice the darker areas between the highlighted filaments! (“Mpc/h” is a unit of galactic distance. 1 Mpc/h is more than 3.2 million light-years)
Photo Credit: Volker Springel, Virgo Consortium

But—what are cosmic voids?!

To put it simply, cosmic voids are areas of our Universe that have an extremely low density (on average less than a tenth of the average density of the Universe). Cosmic voids can be as large as 500 MILLION light years across!

For reference, our Milky Way galaxy is just 100,000 light years in size! In these cosmic voids, galaxies do exist, but they’re immensely rarer to spot than when looking at a non-void section of the Universe.

So—HOW did cosmic voids develop?!

In order to understand this, we need to go back to the very, very early stages of the Big Bang—we’re talking a fraction of a second after the beginning of our Universe. A time when the Universe was a very strange place.

During this time, the entire cosmos was a compressed region of hot ionized gas—a.k.a. plasma. This plasma was mostly uniformed in density, but on the tiniest scale there were variations.

These tiny fluctuations in density became larger and much more pronounced as the Universe continued to expand. The areas with high density eventually became areas that contained clusters of galaxies while the lower density areas became the voids that we see today.

That’s a lot to comprehend! Let’s do a quick thought experiment to make this phenomena easier to visualize.

First we’re going to start off with a deflated balloon.
Pay close attention to what happens to the letters once the balloon is expanded with air.
As you can see, the letters have begun to stretch as the balloon expands!
WOW! What a difference! The letters are now immensely larger than they were before the balloon was inflated.

See?! Just like the letters on the balloon, the tiny areas of low density in our early Universe became HUGE areas of low density (voids) in our current Universe.

This emergent phenomena has also contributed to the hierarchical clustering of the Universe. Hierarchical clustering is when smaller structures coalesce to form larger structures.

Hierarchical Clustering (Illustration by  AstroFan)Phase 1:
Stars, dust, and dark matter cluster to make a Galaxy.Phase 2:
Multiple galaxies coalesce to make a cluster.Phase 3:
Multiple clusters of galaxies form huge galactic filaments that span 200 - 500 millions light years across. Each filament contains countless galaxies!

As you can see in the image above, matter on the tiniest of scales can impact objects on the largest of scales!

Pretty neat, right!?

So, WHY are cosmic voids so significant to our Universe?

Firstly, they make up a HUGE part of our Universe! In fact, 90% of known space is composed of cosmic voids.

Secondly, cosmic voids are also crucially important in understanding how our Universe works. The low-density environment of cosmic voids creates an ideal setting for scientists to study the effects of dark energy on the Universe.

For those who don’t know, dark energy is an UNKNOWN form of energy that is believed to compose almost 70% of the TOTAL ENERGY IN THE UNIVERSE.

Pretty spooky stuff, if you ask me!

But the good news is that cosmic voids are sensitive to cosmological changes (including those caused by dark energy), which means that scientists can study the change in shape and the growth of cosmic voids over time to work towards a better understanding of what dark energy is.

SO, the next time you find yourself pondering over the magnificent objects of our Universe (neutron stars, our Moon, exoplanets, etc), make sure to take the time to give the space around these objects some love too! The colossal beasts that lurk in the dark, remaining ever so elusivecosmic voids!

Stay tuned for more awesome space facts on the next AstroFan.

Thank you for reading!

—Bianca, a.k.a. AstroFan

Adler Staff Star: Meet Lee!

Lee Garcia
Facilities Support Team Lead

You’ve worked at the Adler for 6 years. (WOW!) What is one of your favorite memories from your time here?

Finding love under the stars!

What is your favorite exhibition, sky show, or experience at the Adler? Why?

My favorite exhibit in the building would have to be between The Universe: A Walk Through Space and Time and the Space Visualization Lab. The exhibit, A Walk Through Space and Time, starts you off by explaining the formation of our Universe through a condensed, easy-to-read timeline that begins with the formation of nuclei within the first three minutes of the Big Bang and ends at the current state of our Universe. It’s also one of the exhibits I feel you can spend about an hour or longer just reading and imagining how vast and incredible our Universe is. In the past, I have walked through the exhibit and it left me with questions that were able to be answered once I visited the Space Visualization Lab.

What are a few of your favorite things to do outside the Adler?

I like going to the movies, taking nature hikes, and traveling around the world. I’ve only managed to travel to France, Italy, and Mexico, but I am planning on going somewhere new this year. Location TBD!

Share one interesting fact about yourself!

I can quote the heck out of It’s Always Sunny in Philadelphia!

Why, in your opinion, is space freaking awesome?

Space is freaking awesome because it reminds us how tiny we are compared to the rest of the Universe.