Awesome: Cassini will take Earth’s picture from 900 million miles away

NASA's Cassini spacecraft will take Earth's picture from 898 million miles away.
<i>This post has been updated. See note below.</i>

It’s time to get ready for your not-so-close-up. NASA’s Cassini spacecraft on the far side of Saturn will snap a long-distance portrait of Earth today between 2:27 p.m. and 2:42 p.m. PDT.

[Updated 8:10 a.m.: “Awesome.” Cassini project scientist Linda Spilker echoed sentiments shared around the world in a comment to the Los Angeles Times on Friday.

""It is awesome to know that Cassini can take a picture of our planet from so far away,” Spilker said.]

At Griffith Park in Los Angeles, crowds will wave at Saturn from the observatory’s front lawn, about 898 million miles away.


In Ithaca, N.Y., volunteers from Cornell University’s astronomy department and the Sciencenter will give a series of short talks about Saturn before heading outside to turn their smiling faces to Cassini’s camera.

In Britain, members of the Eddington Astronomical Society of Kendal will gather at the ruins of an 800-year-old castle in Cumbria to observe Saturn through telescopes before the picture-taking begins at 10:27 p.m. local time.

And in Hahamonga Watershed Park in Pasadena, just downhill from Cassini’s birthplace at the Jet Propulsion Laboratory, more than 100 campers and staff from Tom Sawyer Camp will stand in the middle of a field and wave to the eastern sky.

For those who can’t get to a public event, NASA will host a live “Wave at Saturn” webcast from JPL beginning at 2 p.m. You can watch it live right here in the window below.

Before all this interplanetary portrait-taking goes to your head, keep in mind that Earth will take up a mere 1.5 pixels of the final image. The centerpiece will be Saturn and its humongous rings -- especially the diffuse E ring, which is more than 620,000 miles wide.

Awesome images of Saturn and its rings

Cassini will be able to see the rings in great detail because Saturn will be blotting out the sun. As Cassini project scientist Linda Spilker explained on JPL’s Wave at Saturn website, a similar mosaic taken in 2006 revealed that the E ring “had unexpectedly large variations in brightness and color around its orbit. We’ll want to see how that looks seven Earth years and a Saturnian season later, giving us clues to the forces at work in the Saturn system.”

It’s a lucky coincidence that Earth will be visible in the background (just barely).


“Every once in a while, Cassini’s orbit takes us into Saturn’s shadow,” said Scott Edgington, deputy project scientist for the mission at JPL. “What makes this somewhat unique is that Cassini will be spending enough time in Saturn’s shadow to turn the spacecraft and image Saturn and its rings. In one of those footprints will be the Earth, where we will pause and take color images of our home planet.”

Staffers at JPL in La Cañada Flintridge have used the occasion to stir up public interest in Saturn and the Cassini mission. It seems to have worked.

“It’s a cool thing to do!” said Stuart Atkinson, the amateur astronomer and outreach educator who helped organize the event at the British castle.

About 30 students at the A-MAN Inc. STEM Summer Science Academy will don lab coats and astronaut suits before heading to the top level of the Inglewood Civic Center parking structure and waving at Saturn. “They are excited!” said Dr. Bettye Walker, president of A-MAN Inc.


Saturn: Views of rings, moons and more

Even JPL employees are a little giddy about seeing themselves from Saturn’s point of view.

“The first object I aimed my very first telescope at was Saturn,” said Jane Houston Jones, a member of the lab’s Cassini education and public outreach team. “That first glimpse of Saturn’s rings circling the slightly flattened sphere was profound.”

For Edgington, the photo op offers an opportunity for existential reflection.


“A picture of Earth from 900 million miles away gives us a chance to ponder our own place in the universe,” he said. “The Earth in this image, bursting with life, will be only a pale blue pixel -- something very, very small even in our solar system. In the vastness of space filled with so many tiny points of light, just imagine the wonderful things those other tiny points of light could hold.”

The Wave at Saturn campaign prompted scientists involved with NASA’s Messenger mission to Mercury to check whether Earth would make a cameo appearance in any of their spacecraft’s pictures.

It turns out that we’re likely to make an appearance in images Messenger will take at at 4:49 a.m., 5:38 a.m. and 6:41 a.m. PDT today and Saturday as it searchers for natural satellites orbiting the closest planet to the sun.

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