Milky Way Over Mt. Bachelor - Mitch Darby

Apollo 11's Lunar Module Might Still Be Orbiting the Moon

After Neil Armstrong and Buzz Aldrin landed on the Moon 52 years ago today in the Lunar Module (aka Eagle), they rode the ascent stage of the LM back to rendezvous with Michael Collins in the Command Module (aka Columbia). After docking, Eagle was jettisoned and the three astronauts returned to Earth in Columbia. It was presumed that Eagle orbited the Moon until eventually crashing into the surface, but a recent analysis shows that the spacecraft may have entered a stable orbit and is still circling the Moon decades after the end of the mission, a priceless artifact of an historic achievement.

Most spacecraft in lunar orbit suffer from instability in their orbits due to the ‘lumpy’ nature of the lunar gravity which tends to cause the orbits to eventually get so elliptical that they hit the moon.

However, an amateur space fan wanted to narrow down the possible impact location and used orbit modelling software to propagate the orbit forwards in time until it hit the moon. He was surprised to find that it didn’t hit the moon, and remained in a stable orbit for decades, this suggests that the Eagle may still be orbiting the moon over 5 decades after being left there.

The paper detailing the analysis suggests that if Eagle has survived, it should be detectable by radar.

The planet Uranus. Taken on November 14th 2009 at 3:52 am. Using the 98 in Hooker telescope.

A view from Mars. Earth, Jupiter, and Venus

The Sun rises over Earth in a postcard illustrated by Soviet cosmonaut Alexei Leonov, recalling the 1965 mission when he became the first human to walk in space.

The Last Shuttle, Dan Winters

All here…

PLUTO

latest Pluto images released Sept 10, 2015 by NASA. Second to last is Pluto’s moon Charon. Last is the original “up close” image of Pluto. Images taken by NASA’s New Horizons Spacecraft.

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Here's What 10 Million Stars Look Like

Using the Dark Energy Camera at the Cerro Tololo observatory in Chile, astronomers took an image of the stars clustered around the center of our Milky Way galaxy that shows about 10 million stars. Check out the zoomable version for the full experience.

Looking at an image like this is always a bit of a brain-bender because a) 10 million is a huge number and b) the stars are so tightly packed into that image and yet c) that image shows just one tiny bit of our galactic center, d) our entire galaxy contains so many more stars than this (100-400 billion), and e) the Universe perhaps contains as many as 2 trillion galaxies. And if I’m remembering my college math correctly, 400 billion × 2 trillion = a metric crapload of stars. (via bad astronomy)

Earth from Afar

“It suddenly struck me that that tiny pea, pretty and blue, was the Earth. I put up my thumb and shut one eye, and my thumb blotted out the planet Earth. I didn’t feel like a giant. I felt very, very small.” - Neil Armstrong, Apollo 11

This week we’re celebrating Earth Day 2018 with some of our favorite images of Earth from afar…

At 7.2 million Miles…and 4 Billion Miles

Voyager famously captured two unique views of our homeworld from afar. One image, taken in 1977 from a distance of 7.3 million miles (11.7 million kilometers) (above), showed the full Earth and full Moon in a single frame for the first time in history. The second (below), taken in 1990 as part of a “family portrait of our solar system from 4 billion miles (6.4 billion kilometers), shows Earth as a tiny blue speck in a ray of sunlight.” This is the famous “Pale Blue Dot” image immortalized by Carl Sagan.

“This was our willingness to see the Earth as a one-pixel object in a far greater cosmos,” Sagan’s widow, Ann Druyan said of the image. “It’s that humility that science gives us. That weans us from our childhood need to be the center of things. And Voyager gave us that image of the Earth that is so heart tugging because you can’t look at that image and not think of how fragile, how fragile our world is. How much we have in common with everyone with whom we share it; our relationship, our relatedness, to everyone on this tiny pixel.“

A Bright Flashlight in a Dark Sea of Stars

Our Kepler mission captured Earth’s image as it slipped past at a distance of 94 million miles (151 million kilometers). The reflection was so extraordinarily bright that it created a saber-like saturation bleed across the instrument’s sensors, obscuring the neighboring Moon.

Hello and Goodbye

This beautiful shot of Earth as a dot beneath Saturn’s rings was taken in 2013 as thousands of humans on Earth waved at the exact moment the spacecraft pointed its cameras at our home world. Then, in 2017, Cassini caught this final view of Earth between Saturn’s rings as the spacecraft spiraled in for its Grand Finale at Saturn.

‘Simply Stunning’

”The image is simply stunning. The image of the Earth evokes the famous ‘Blue Marble’ image taken by astronaut Harrison Schmitt during Apollo 17…which also showed Africa prominently in the picture.“ -Noah Petro, Deputy Project Scientist for our Lunar Reconnaissance Orbiter mission.

Goodbye—for now—at 19,000 mph

As part of an engineering test, our OSIRIS-REx spacecraft captured this image of Earth and the Moon in January 2018 from a distance of 39.5 million miles (63.6 million kilometers). When the camera acquired the image, the spacecraft was moving away from our home planet at a speed of 19,000 miles per hour (8.5 kilometers per second). Earth is the largest, brightest spot in the center of the image, with the smaller, dimmer Moon appearing to the right. Several constellations are also visible in the surrounding space.

The View from Mars

A human observer with normal vision, standing on Mars, could easily see Earth and the Moon as two distinct, bright "evening stars.”

Moon Photobomb

“This image from the Deep Space Climate Observatory (DSCOVR) satellite captured a unique view of the Moon as it moved in front of the sunlit side of Earth in 2015. It provides a view of the far side of the Moon, which is never directly visible to us here on Earth. “I found this perspective profoundly moving and only through our satellite views could this have been shared.” - Michael Freilich, Director of our Earth Science Division.

Eight Days Out

Eight days after its final encounter with Earth—the second of two gravitational assists from Earth that helped boost the spacecraft to Jupiter—the Galileo spacecraft looked back and captured this remarkable view of our planet and its Moon. The image was taken from a distance of about 3.9 million miles (6.2 million kilometers).

A Slice of Life

Earth from about 393,000 miles (633,000 kilometers) away, as seen by the European Space Agency’s comet-bound Rosetta spacecraft during its third and final swingby of our home planet in 2009.

So Long Earth

The Mercury-bound MESSENGER spacecraft captured several stunning images of Earth during a gravity assist swingby of our home planet on Aug. 2, 2005.

Earth Science: Taking a Closer Look

Our home planet is a beautiful, dynamic place. Our view from Earth orbit sees a planet at change. Check out more images of our beautiful Earth here.

Join Our Earth Day Celebration!

We pioneer and supports an amazing range of advanced technologies and tools to help scientists and environmental specialists better understand and protect our home planet - from space lasers to virtual reality, small satellites and smartphone apps. 

To celebrate Earth Day 2018, April 22, we are highlighting many of these innovative technologies and the amazing applications behind them.

Learn more about our Earth Day plans HERE. 

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The Moon in Motion

Happy New Year! And happy supermoon! Tonight, the Moon will appear extra big and bright to welcome us into 2018 – about 6% bigger and 14% brighter than the average full Moon. And how do we know that? Well, each fall, our science visualizer Ernie Wright uses data from the Lunar Reconnaissance Orbiter (LRO) to render over a quarter of a million images of the Moon. He combines these images into an interactive visualization, Moon Phase and Libration, which depicts the Moon at every day and hour for the coming year. 

Want to see what the Moon will look like on your birthday this year? Just put in the date, and even the hour (in Universal Time) you were born to see your birthday Moon.

Our Moon is quite dynamic. In addition to Moon phases, our Moon appears to get bigger and smaller throughout the year, and it wobbles! Or at least it looks that way to us on Earth. This wobbling is called libration, from the Latin for ‘balance scale’ (libra). Wright relies on LRO maps of the Moon and NASA orbit calculations to create the most accurate depiction of the 6 ways our Moon moves from our perspective.

1. Phases

The Moon phases we see on Earth are caused by the changing positions of the Earth and Moon relative to the Sun. The Sun always illuminates half of the Moon, but we see changing shapes as the Moon revolves around the Earth. Wright uses a software library called SPICE to calculate the position and orientation of the Moon and Earth at every moment of the year. With his visualization, you can input any day and time of the year and see what the Moon will look like!

2. Shape of the Moon

Check out that crater detail! The Moon is not a smooth sphere. It’s covered in mountains and valleys and thanks to LRO, we know the shape of the Moon better than any other celestial body in the universe. To get the most accurate depiction possible of where the sunlight falls on the lunar surface throughout the month, Wright uses the same graphics software used by Hollywood design studios, including Pixar, and a method called ‘raytracing’ to calculate the intricate patterns of light and shadow on the Moon’s surface, and he checks the accuracy of his renders against photographs of the Moon he takes through his own telescope.

3. Apparent Size 

The Moon Phase and Libration visualization shows you the apparent size of the Moon. The Moon’s orbit is elliptical, instead of circular - so sometimes it is closer to the Earth and sometimes it is farther. You’ve probably heard the term “supermoon.” This describes a full Moon at or near perigee (the point when the Moon is closest to the Earth in its orbit). A supermoon can appear up to 14% bigger and brighter than a full Moon at apogee (the point when the Moon is farthest from the Earth in its orbit). 

Our supermoon tonight is a full Moon very close to perigee, and will appear to be about 14% bigger than the July 27 full Moon, the smallest full Moon of 2018, occurring at apogee. Input those dates into the Moon Phase and Libration visualization to see this difference in apparent size!

4. East-West Libration

Over a month, the Moon appears to nod, twist, and roll. The east-west motion, called ‘libration in longitude’, is another effect of the Moon’s elliptical orbital path. As the Moon travels around the Earth, it goes faster or slower, depending on how close it is to the Earth. When the Moon gets close to the Earth, it speeds up thanks to an additional pull from Earth’s gravity. Then it slows down, when it’s farther from the Earth. While this speed in orbital motion changes, the rotational speed of the Moon stays constant. 

This means that when the Moon moves faster around the Earth, the Moon itself doesn’t rotate quite enough to keep the same exact side facing us and we get to see a little more of the eastern side of the Moon. When the Moon moves more slowly around the Earth, its rotation gets a little ahead, and we see a bit more of its western side.

5. North-South Libration

The Moon also appears to nod, as if it were saying “yes,” a motion called ‘libration in latitude’. This is caused by the 5 degree tilt of the Moon’s orbit around the Earth. Sometimes the Moon is above the Earth’s northern hemisphere and sometimes it’s below the Earth’s southern hemisphere, and this lets us occasionally see slightly more of the northern or southern hemispheres of the Moon! 

6. Axis Angle

Finally, the Moon appears to tilt back and forth like a metronome. The tilt of the Moon’s orbit contributes to this, but it’s mostly because of the 23.5 degree tilt of our own observing platform, the Earth. Imagine standing sideways on a ramp. Look left, and the ramp slopes up. Look right and the ramp slopes down. 

Now look in front of you. The horizon will look higher on the right, lower on the left (try this by tilting your head left). But if you turn around, the horizon appears to tilt the opposite way (tilt your head to the right). The tilted platform of the Earth works the same way as we watch the Moon. Every two weeks we have to look in the opposite direction to see the Moon, and the ground beneath our feet is then tilted the opposite way as well.

So put this all together, and you get this:

Beautiful isn’t it? See if you can notice these phenomena when you observe the Moon. And keep coming back all year to check on the Moon’s changing appearance and help plan your observing sessions.

Follow @NASAMoon on Twitter to keep up with the latest lunar updates. 

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