Articles

Marc Rayman

Marc Rayman's latest Dawn journal explains the temperature adjustments engineers make to save power and keep the spacecraft warm.

Emily Lakdawalla

Really cool movies from Jim Richardson propose to explain how the same physics of impact cratering can produce such differently-appearing surfaces as those of the Moon, large asteroids like Eros, and teeny ones like Itokawa.

Emily Lakdawalla

Before yesterday, my answer to this question would be

Emily Lakdawalla

This week I'll be talking with NEOWISE principal investigator Amy Mainzer about moving objects that the WISE mission has spotted both inside and outside our solar system.

Karl Battams

Comet PANSTARRS is delighting northern hemisphere viewers right now. But it's also big, bright, and beautiful to the STEREO spacecraft.

Emily Lakdawalla

JPL's Solar System Dynamics group shows that there is still a possibility that C/2013 A1 (Siding Spring) could hit Mars. But the uncertainty in its position at that time is large -- the closest approach could happen an hour earlier, or an hour later -- so we're a long way from knowing yet whether it will or (more likely) won't impact.

Emily Lakdawalla

Last week I trawled the archives to find all of Galileo's images of asteroid Ida; this week, I turned to Gaspra.

Marc Rayman

Now that Dawn has changed its speed by nearly eight kilometers per second, Marc Rayman revisits the concept of orbital velocity.

Emily Lakdawalla

Emily Lakdawalla's guest this week was Applied Physics Laboratory asteroid astronomer Andy Rivkin. We talked about the menagerie of rocks in the asteroid belt, how many of them travel in pairs and triples, how some of them are surprisingly wet, and how much you can learn about asteroids using Earth-based telescopes.

Emily Lakdawalla

A recently discovered comet, C/2013 A1 (Siding Spring), is going to be passing very close to Mars on October 19, 2014. Does it pose a risk to spacecraft?

Emily Lakdawalla

While writing up the cruise-phase issues of the Galileo Messenger a couple of weeks ago, I came across a fuzzy montage of images of Ida that I had not seen before. So I decided to spend some time digging into the Planetary Data System to see if there were more images to be found. I found lots and lots pictures that I'd never seen before!

Mat Kaplan

Professor Bell's topic is

Emily Lakdawalla

A frequently-asked question last week was: if asteroid 2012 DA14 is coming so close to Earth, why hasn't anyone taken any pictures of it? Now that 2012 DA14 has whizzed past us, we do finally have some radar pictures of it, but they still may not satisfy everyone.

Louis D. Friedman

Executive Director Emeritus Louis Friedman writes about Asteroid programs of The Planetary Society.

Edward Gomez

Mostly the Universe stays unchanged for hundreds, thousands or even millions of years. There are some cases however when some things change really rapidly. Recently I observed one of these rapidly changing, transient phenomena, as asteroid called 2012 DA14. I work for Las Cumbres Observatory and we have been trying to observe this asteroid since 5 February.

Mat Kaplan

SEE IT NOW: The Planetary Society's CEO, Bill Nye the Science Guy, joined Director of Projects Bruce Betts for a live webcast as 2012 DA14, a 45-meter asteroid, was passing Earth. Bill and Bruce also marveled at video of the meteor burst high over a city in Russia.

Emily Lakdawalla

Last week, I posted an explainer on why Hubble's images of galaxies show so much more detail than its images of Pluto. Then I set you all a homework problem: when will New Horizons be able to see Pluto better than Hubble does? Here's the answer.

Emily Lakdawalla

A large meteor streaked through the skies above Russia on the morning of Feb 15th, causing a deafening sonic boom that shattered windows and injured hundreds.

Heidi Hammel

Preliminary estimates show that the meteoroid was 15 meters wide and weighed roughly 8000 tons. The resulting airburst would have the equivalent yield of about a 1/2 megaton explosion.

Emily Lakdawalla

How come Hubble's pictures of galaxies billions of light years away are so beautifully detailed, yet the pictures of Pluto, which is so much closer, are just little blobs? I get asked this question, or variations of it, a lot. Here's an explainer.