The Adler 'Scope

Featured Article

Image of moon

A Total Lunar Eclipse

Public Observing

Did you get to see the lunar eclipse this past January right before sunrise? It was tough to see. The Moon was low in the west, and we didn’t get to view the entire eclipse because the Moon set before the eclipse finished. Folks out in the western U.S. got a much better chance to see it than we did since the Moon was higher in the sky for them than it was for us. But on January 20, 2019, if the weather is clear, we’ll be treated to a great lunar show in the sky from start to finish!

A lunar eclipse occurs when the Sun, Earth, and Moon are perfectly aligned. Sunlight falls on Earth, and Earth casts its shadow into space. The Moon’s orbit is tilted a bit with respect to the Earth, so as the Moon orbits Earth, usually the Moon passes a bit above or below the shadow. But, when the Moon passes through the Earth’s shadow, we see the Moon turn brown, red, orange, or gray. This is called a lunar eclipse. If you were standing on the surface of the Moon, the Earth would appear to eclipse the Sun.

The next lunar eclipse visible from the Chicago area will be on January 20, 2019—a Sunday night. The Moon will be in the eastern sky when the eclipse starts at 8:36 pm CST. As it begins to pass into the lighter part of the Earth’s shadow, the color of the Moon will start to change from bright light gray to a progressively deeper tan. Starting at 9:33 pm CST, the Moon will begin to encounter the darker part of the Earth’s shadow and look a bit like a cookie with a bite taken out of it. At 10:41 pm CST, the Moon will be fully within the Earth’s shadow, looking dark red or dark gray. This is called totality. Totality ends at 11:43 pm CST, and the Earth exits the darker part of the Earth’s shadow at 12:50 am CST on January 21. The Moon fully exits the lighter part of the Earth’s shadow at 1:48 am CST on January 21.

If it is clear out and you are away from tall buildings and trees, you should have no trouble spotting the eclipse. The Moon will be high in the sky to the east, southeast, and south. Remember: It will be January, so if it is clear out, it may be VERY cold. Don’t forget to bundle up warmly and grab some hot cocoa or coffee!

Read More

Latest Articles

Moon rising over the Adler Planetarium

Once in a Blue Moon

Mark Hammergren Astronomy

For decades, NASA’s plans for human space exploration have focused on Mars as the preeminent target. However, in December 2017, the Trump administration issued a national policy directive through its freshly reconstituted Space Council calling for a return to the Moon—not just with Apollo-style landings, but “for long-term exploration and utilization.” Over the next couple decades, NASA’s efforts may focus on the establishment of a lunar base in the style of Antarctic research centers or the International Space Station—continuously staffed but relying on supplies from Earth.But there are those who look to the Moon as a place where humanity will found an independent, self-sufficient existence.

The rationale goes beyond George Mallory’s famous quip about his reason for climbing Mount Everest:“Because it’s there.” Instead of being a goal in and of itself, lunar exploration is seen as a path to the extraction of valuable and even unique resources. Perhaps chief among these is helium-3, a light, non-radioactive isotope of helium that is implanted into the lunar surface via the solar wind and could be readily mined from the lunar soil (or regolith). Helium-3 is a potential source of clean nuclear fusion energy once such reactor technology is developed.

Water is another resource that is plentiful on the Moon—surprisingly so, given the stark, airless environment, which is subject nearly everywhere to enormous temperature extremes. In addition to ice deposits found in permanently shadowed (and thus extremely cold) polar craters, vast stretches of the lunar surface have been found to contain tiny concentrations of water outgassed from the Moon’s interior or generated in interactions with the solar wind. Water could be conventionally mined from the poles or simply baked out of the lunar regolith by roving, robotic ovens. As a resource, water is incredibly useful for several reasons: as liquid for human consumption, broken into its constituent elements for oxygen for breathing, and for the combination of hydrogen and oxygen as rocket fuel.

Even more ambitious visionaries see a future in which human existence on the Moon is not limited to isolated, enclosed habitats, but one in which the whole environment of the Moon has been altered or “terraformed” into a small version of Earth. The generation of an oxygen atmosphere thick enough to support life could be accomplished by impacting hundreds of comets the size of Halley’s Comet onto the Moon—a task impossible with current technology, but perfectly feasible given straightforward physics. Although the Moon’s low gravity means that oxygen atoms would escape into space far more readily than from Earth and any atmosphere would only be temporary, the timescale for such loss could still extend into millions of years. This is short on geological scales, explaining the Moon’s current airless state, but long in personal human terms.

Indeed, there is evidence that the Moon may have possessed a short- lived atmosphere billions of years ago. Several rocks recovered from the Moon by Apollo 16 astronauts were found to contain bits of natural iron that had somehow rusted—a process requiring the presence of oxygen and liquid water. Models of cometary impacts and volcanic activity suggest that temporary lunar atmospheres may have been formed many times over the past four billion years.

Whatever the scope of future human activity on the Moon, it is likely that someday we will return, and it may just be that this time it will be forever.

Catch a total lunar eclipse in Chicago this January!

Adler Skywatch: January 2019

Karen Donnelly Astronomy, Public Observing

Bright stars and planets, meteors, an eclipse, a “Supermoon,” and a close approach by the Sun are all expected during January 2019.

In evening twilight this month, the planet Mars is high in the southern skies. The night of the 12th, it appears near a waxing crescent Moon. Each evening Mars appears higher in the sky than the night before; but it also gets slightly dimmer each night, as it moves further from Earth after its close approach last summer. By about 10:00 pm CT, Mars is very low in the west.

The rest of the month’s planetary viewing occurs during early-morning darkness. The two brightest planets, Venus and Jupiter, are above the southeast horizon by 6:00 am CT. Venus is the brighter of the two—though both are brighter than any of the stars in the night sky. From the 1st through the 24th, Venus appears higher than Jupiter. But on the 25th and 26th they appear at about the same altitude. By the 28th Jupiter appears higher than Venus. A waning crescent Moon appears between the two planets on the 31st.

The planets Mercury and Saturn appear so close to the Sun this month that they are difficult if not impossible to view.

Perihelion, when the Sun is closest to Earth for the year, occurs on the 2nd, at 11:19 pm CT. At perihelion, Earth is about 91.4 million miles from the Sun, which is about 3 million miles closer than it is at its furthest, which occurs in early July.

Also in January, the annual Quadrantids Meteor Shower peaks the night of the 3rd and morning of the 4th. From very dark, very clear skies, a peak of about 40 meteors per hour is expected. This year the waning crescent Moon doesn’t rise until morning twilight on the 4th, so it won’t interfere with the sky’s darkness. The Quadrantids appear to radiate from the constellation Boötes, which rises in the northeast around midnight Central time—but the meteors can appear anywhere in the sky. No special equipment is needed—just dress warmly for the weather, and look up!

The month’s biggest astronomical event is the night of the 20th, when a total lunar eclipse is visible from most of North and South America. In the Chicago area, the partial phase of the eclipse starts about 9:34 pm Central time, as the Moon slips into Earth’s shadow. Totality, when the Moon is entirely within Earth’s shadow, begins at 10:41 pm. During totality the Moon is likely to turn a deep reddish color. Totality ends at 11:43 pm; and the partial phase ends at 12:50 am on the 21st. Look now while you can, because this is the last total lunar eclipse anywhere until May 2021.

The 20th is also the night of 2019’s first “Supermoon”—a Full or New Moon near perigee, the point in the Moon’s orbit when it’s closest to Earth. A Supermoon often looks slightly larger than a usual Moon. This year the February and March Full Moons will also be considered Supermoons.

New Moon: January 5th
First Quarter Moon: January 14th
Full Moon: January 20th
Last Quarter Moon: January 27th

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

Header photo credit: DanielaC173 on Foter.com / CC BY-SA

Image of moon

A Total Lunar Eclipse

Michelle Nichols Public Observing

Did you get to see the lunar eclipse this past January right before sunrise? It was tough to see. The Moon was low in the west, and we didn’t get to view the entire eclipse because the Moon set before the eclipse finished. Folks out in the western U.S. got a much better chance to see it than we did since the Moon was higher in the sky for them than it was for us. But on January 20, 2019, if the weather is clear, we’ll be treated to a great lunar show in the sky from start to finish!

A lunar eclipse occurs when the Sun, Earth, and Moon are perfectly aligned. Sunlight falls on Earth, and Earth casts its shadow into space. The Moon’s orbit is tilted a bit with respect to the Earth, so as the Moon orbits Earth, usually the Moon passes a bit above or below the shadow. But, when the Moon passes through the Earth’s shadow, we see the Moon turn brown, red, orange, or gray. This is called a lunar eclipse. If you were standing on the surface of the Moon, the Earth would appear to eclipse the Sun.

The next lunar eclipse visible from the Chicago area will be on January 20, 2019—a Sunday night. The Moon will be in the eastern sky when the eclipse starts at 8:36 pm CST. As it begins to pass into the lighter part of the Earth’s shadow, the color of the Moon will start to change from bright light gray to a progressively deeper tan. Starting at 9:33 pm CST, the Moon will begin to encounter the darker part of the Earth’s shadow and look a bit like a cookie with a bite taken out of it. At 10:41 pm CST, the Moon will be fully within the Earth’s shadow, looking dark red or dark gray. This is called totality. Totality ends at 11:43 pm CST, and the Earth exits the darker part of the Earth’s shadow at 12:50 am CST on January 21. The Moon fully exits the lighter part of the Earth’s shadow at 1:48 am CST on January 21.

If it is clear out and you are away from tall buildings and trees, you should have no trouble spotting the eclipse. The Moon will be high in the sky to the east, southeast, and south. Remember: It will be January, so if it is clear out, it may be VERY cold. Don’t forget to bundle up warmly and grab some hot cocoa or coffee!

Jim Lovell

Dream Big

Annie Vedder Behind the Scenes

It takes a great deal of confidence to make our visions reality. I understand this firsthand because, like so many people, I’ve had ambitious ideas, but had no idea how to make them come to fruition.

In 2014, I had the opportunity to update the exhibit about Captain Jim Lovell’s life and contributions to getting humanity to the Moon and back. Working on this exhibit would be a massive opportunity for me professionally, and the pressure was on. At the time, it felt like a daunting task with limitless possibilities, but no clear way to begin. I took inspiration from the man I was researching and decided to take action on my crazy ideas and not to fear failure because failure is part of the process. It would take a year to complete the project, and there were many ups and downs along the way; but in April 2015, ideas that existed only as dreams and crazy ideas became a reality. Mission Moon opened to the public.

Captain Lovell has inspired generations to look up, explore, and achieve the impossible. To commemorate his 90th birthday, we updated Mission Moon by launching Letters to Lovell. We asked you to share how Captain Lovell’s story has encouraged you to pursue your dreams and find new frontiers to explore in a letter-writing campaign. So far, you have shared your dreams and aspirations parallel to Captain Lovell’s boyhood dream of becoming a rocket engineer, launching rockets, and becoming an astronaut. Perhaps people dismissed Captain Lovell’s ambitions as boyhood daydreams—and there indeed was a lot of uncertainty—but like so many of us, Captain Lovell’s drive and willingness to act on opportunities as they presented themselves helped him make his dreams a reality.

What are your dreams? Does your future career currently exist, or will you need to forge a path and open new frontiers? Will you need to engineer the ideas that only exist in your imagination?

Change and infinite possibilities are on the horizon. The way we live, work and relate to one another will be fostered by you. Take inspiration from Captain Lovell: Dream big and don’t let the fear of failure stop you from making your dreams a reality. You will reinvent the world, again and again, and again. Thank you, Captain Lovell, for this amazing legacy.

Adler Staff Star: Meet Yolanda!

Behind the Scenes

Yolanda V.
Guest Services Shift Supervisor 

What do you enjoy the most about working at the Adler?
What I enjoy most about working at the Adler is leading a great team on a daily basis and watching them give our guests memorable experiences.

What is one of your favorite memories from your time at the Adler?
One of my favorite memories at the Adler was our Eclipse 2017 event. It was crazy to see how many people we hosted at once!

Why, in your opinion, is space freaking awesome?
I think space is freaking awesome because we keep discovering new things all the time.

What do you like to do outside the Adler?
I like to go out with friends and do fun activities with them, like going to concerts and checking out new restaurants.

Share one interesting fact about yourself!
I once climbed the pyramids in Mexico!

Earthrise- photo taken by Bill Anders on December 24, 1968

Sailing to the Moon and Back

Dr. Andrew Johnston Astronomy, Collections

This December, we celebrate the 50th anniversary of the Apollo 8 mission to the Moon, one of the most amazing journeys of exploration in human history. This was the first time humans ever ventured away from Earth’s immediate vicinity, and the first time anyone saw both sides of the Moon with their own eyes.

On Christmas Eve of 1968, Apollo 8 astronauts Frank Borman, William Anders, and James Lovell were on the far side of the Moon, out of contact with Earth. A rocket boost was required to enter lunar orbit. Too much of a burn and the spacecraft would crash into the surface. Too little and the crew would be sent into a trajectory that could have made it impossible for them to return home.The maneuver, perhaps the riskiest of the whole mission, was executed perfectly. After a journey of almost a quarter of a million miles, it hit its target: an altitude of about sixty miles above the lunar surface. The success of Apollo 8 lead to the subsequent Apollo missions that landed on the lunar surface.

Leading up to the Moon missions, NASA and its contractors had to address many challenges. Among the biggest: How could a spacecraft be navigated with pinpoint accuracy all the way to the Moon and back?

The earlier Gemini spaceflights of the 1960s tested solutions for space navigation. Lovell also flew on Gemini XII, the final flight of the Gemini program, with astronaut Buzz Aldrin. In the spacecraft was a sextant which Aldrin used to take readings of star positions. Today the Gemini XII spacecraft is displayed at the Adler. You can see where the sextant was stowed on the interior “ceiling” between the two hatches.

Developed after extensive testing, the Apollo navigation systems included celestial navigation based on measuring star positions and radio navigation using signals from Earth. For centuries, navigators have used tools such as sextants and chronometers to determine position. Just like sailing ships, the Apollo spacecraft carried sextants. These worked on the same principles used by historic sextants in the collections of the Adler Planetarium.

During flights to the Moon, an astronaut would maneuver the spacecraft to make a star visible in the sextant, measure the angle between the star and Earth, then enter a code into the computer. James Lovell had primary responsibility for testing the navigation system during Apollo 8. Lovell made more than 70 sextant sightings on the way to the Moon and a similar number on the return journey. Lovell performed more celestial navigation sightings in space than any other person, a mark that stands to this day. By the end of the Apollo 8 mission, both the celestial and radio methods of navigation were in almost perfect agreement.

The journey to the Moon was followed by the crew’s dramatic Christmas Eve reading from the book of Genesis and the “Earthrise” image, one of the most famous photographs ever taken. Later, another rocket burn was required to leave lunar orbit and get back to Earth. To everyone’s relief, the crew made radio contact when they emerged from behind the Moon on the correct trajectory. Lovell reported back to Mission Control, “Please be informed there is a Santa Claus!”

Apollo 8 proved to be a unique turning point for space exploration. It was the last time humans extensively tested traditional celestial navigation techniques in space. For future Apollo missions the ground-based radio positioning took precedence. The space travelers of Apollo 8 expanded the human presence beyond the Earth for the first time. Along the way they briefly navigated in the manner of eighteenth- and nineteenth-century sea captains, connecting their voyage with centuries of human ingenuity and innovation.

Blog Subscription

Sign Up For Exclusive Content!

Need some Space in your inbox? Subscribe to our newsletter to be the first to receive the latest news on Adler programs, events, and happenings.

Resources