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Comet 67P/Churyumov-Gerasimenko, rosetta, rosetta spacecraft

Philae Phones Home

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Rosetta’s Lander says “Can You Hear Me Now?”

Artist’s conception of the Philae lander on the surface of Comet 67P/Churyumov-Gerasimenko. In reality, it landed somewhere near a large cliff, and teams are still pinpointing the spot. ESA/ATG medialab

I woke up today to great news that the Rosetta mission’s Philae lander has been awake for a short time now and finally was able to phone home. The mission controllers reported that it talked with the ground team for about 85 seconds, sending data. More than 300 packets have been analyzed and the team is hoping to retrieve more than 8,000 data packets stored on the lander’s onboard memory.  That information would give the science teams a good look at the most recent experiences Philae has had since waking up at some point before it phoned home.

This is really fantastic news, folks. It means that — if Philae stays awake and communicative — that we’ll have “boots on the ground” during the comet’s perihelion passage in mid-August. We’ll get reports from the comet as it warms up during closest approach to the Sun, and get some great images of the landscapes during that time, not to mention temperature and other data.

Want to follow along on Philae’s adventure? I’ll write about it as it comes and you can always go check out the Rosetta Blog for the latest updates!  I’ve written more about the Rosetta mission here and here.

Good to hear from you, Philae!  And, now Rosetta scientists can figure out just where you’re resting by using your signals to triangulate in on you.

 

comet, Comet 67P/Churyumov-Gerasimenko, comet dust, rosetta, rosetta spacecraft

Snake Eyes on a Comet

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Weird-looking Jets from Comet 67P Tell Tales of Interior Activity

This image of Rosetta’s comet taken on April 25, 2015 from a distance of approximately 93 kilometers (57 miles) shows clearly distinguishable dust jets persisting after nightfall. (Click image for a larger view.) ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA

The Rosetta Mission’s OSIRIS camera team released an image of jets blasting out from beneath the dusty surface of Comet 67P/Churyumov-Gerasimenko. The instant I saw the image, the jets reminded me of fangs on an alien snake or laser-like eyes on some strange sci-fi monster (how’s that for some Monday-morning pareidolia?). Actually, the truth is far more interesting than fiction.

What we’re looking at here is what happens when the Sun warms a comet. It’s a view of two jets on the side of the comet that will shortly be in darkness. And therein lies an interesting suggestion about jet activity on 67P. All along, since Rosetta arrived at the comet, we’ve been getting treated to increasing amounts of jet activity as 67P gets closer to the Sun and gets heated up. But, until recently, the jets were only active on the daylight side of the comet. Now, they’re persisting after sunset, and showing up prior to sunrise. So, what has changed?

The answer is pretty simple: as the comet gets closer to the Sun, its activity is increasing. The OSIRIS team suggests that the comet can store heat beneath the dusty crust, and the deeper layers remain warm quite a while after sunset and after the surface cools. This isn’t a new idea, since other comets have shown similar post-sunset activity, but this is the first time that astronomers have been able to get a good, high-resolution look at post-sunset jets on a comet. It’s the kind of detail that will help comet scientists understand their targets better.

Comet 67P has its closest approach to the Sun on August 13, 2015, and the Rosetta spacecraft will be tracking right along with it through this incredibly busy (and somewhat dangerous) time. For some comets, perihelion passage can break them apart. Comet 67P may not face as much danger as sun-grazing comets that come too close to the Sun. That’s because the closest it will come to the Sun is 186 million kilometers (115 million miles). Earth is 150 million kilometers (93 million miles) away, so that puts the comet’s perihelion distance at outside the orbit of Earth. Still, the comet should show quite a bit more activity, which the spacecraft will be documenting along the way. Stay tuned!