APOD: Philae Attempts Comet Nucleus Landing (2014 Nov 12)

[APOD Robot]

Philae Attempts Comet Nucleus Landing

Explanation: Today humanity will make its first attempt to land a probe on the nucleus of a comet. As the day progresses, the Philae (fee-LAY) lander will separate from the Rosetta spacecraft and head down to the surface of Comet 67P/Churyumov–Gerasimenko. Since the texture of the comet's surface is unknown and its surface gravity is surely low, Philae will then attempt to harpoon itself down, something that has never been done before. Featured here is an artist's illustration of dishwasher-sized Philae as it might look on Comet Churyumov–Gerasimenko's surface, along with explanation balloons detailing onboard scientific instruments. Many people on a blue planet across the Solar System will be eagerly awaiting news and updates. Whether Philae actually lands, whether it lands on a smooth patch, whether the harpoons take hold, and how far the robotic lander sinks into the surface should all become known as events unfold today.

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[Nitpicker]

A newspaper report I read yesterday quoted someone from the team estimating a 50% chance of successful landing, which should be considered as "icing on the cake", since 80% of the science program has been, or will be done by the orbiting Rosetta. Well, I think I can speak for most icing lovers with a "bonne chance" to the team. (No pressure.)

[geckzilla]

That's an odd mix of pessimism and optimism, Nit! Everyone knows the odds aren't fantastic for Philae but most sources are acting optimistic. The truth is that there is a real chance the news will break tomorrow and Philae will have suffered some catastrophe. I really hope that's not the case because ESA's done a pretty good job of getting us attached to the little fellow with cartoons and animations. While a success would be icing on the Rosetta cake, a failure would be anti-icing on the anti-cake*. We could use some positive news.

*Ingredients: Broken rocket parts, the soul of a pilot, and the crushed dreams of aspiring space enthusiasts everywhere

[Nitpicker]

Not pessimism, just parroting what I read in da paper. (I have a 0% chance of landing anything on a comet any time soon.)

[geckzilla]

Yes, I meant that newspaper report was a funny mixture, not you...parrot.

[MargaritaMc]

http://asterisk.apod.com/viewtopic.php? ... &start=100

[rstevenson]

A heads up to anyone tempted to click the "across the Solar System" link in the APOD description. That page caused my 7-year old iMac to bomb out, probably due to insufficient graphics resources. I had to go online in a different browser, track down arcane info on how to restart FF without automatically opening that tab, and then had to go spelunking in my system resources to find a particular file to throw it away. (Apparently FF doesn't have an easy keyboard shortcut to allow opening it without opening previously open tabs.) So if you have an older computer, be wary of that link.

Rob

[sandcastlecontractor]

So now, Philae will take attempt to take pictures of the universe ridding piggy back on comet 67P/CG..

[FloridaMike]

A heads up to anyone tempted to click the "across the Solar System" link in the APOD description. That page caused my 7-year old iMac to bomb out, probably due to insufficient graphics resources. I had to go online in a different browser, track down arcane info on how to restart FF without automatically opening that tab, and then had to go spelunking in my system resources to find a particular file to throw it away. (Apparently FF doesn't have an easy keyboard shortcut to allow opening it without opening previously open tabs.) So if you have an older computer, be wary of that link.

Rob

You are not missing much. Just a beautifully portrayed 3D animation of Rosetta's the flight path through the inner solar system. Pretty neat how we can rotate the solar system and view it edge on. Orbital mechanics is just plain fun.

[Boomer12k]

GOOD LUCK, PHILAE!!!!

Hope all goes well!

:---[===] *

[tannaberton]

If we knew how comets are really asteroids with a wide orbit. how can we expect (since we knew comets are rocks 10 years ago) this thing to drill into rock with "ice drills?" I am wondering how far it will bounce and why bother in th efirst place?????

[Chris Peterson]

If we knew how comets are really asteroids with a wide orbit. how can we expect (since we knew comets are rocks 10 years ago) this thing to drill into rock with "ice drills?" I am wondering how far it will bounce and why bother in th efirst place?????

Comets and asteroids are different things. They formed in different places under different conditions. Asteroids are rocky bodies, some partly differentiated. Comets are icy bodies. That doesn't mean that comets don't contain rocky material. But the surface of most comets is dominated by ices. Philae is designed to be able to drill into both ice and rock. (And very cold ice isn't all that different from rock when it comes to drilling.)

[alter-ego]

Congratulations!
Successful landing & sending telemetry data - 16:10 UTC

[Cousin Ricky]

I’m tempted to remark that APOD has fallen for CNN Syndrome: “We Bring You the News Before It Happens.” At least today’s graphic displays useful information. According to ESA’s Web site, Philae should be landing as I’m posting this, but no word yet.

---

CORRECTION. I must have visited the page mere seconds prior to 16:10 UTC. Congratulations to ESA!

[BMAONE23]

http://www.nbcnews.com/science/space/hi ... ay-n246671

[geckzilla]

I’m tempted to remark that APOD has fallen for CNN Syndrome: “We Bring You the News Before It Happens.” At least today’s graphic displays useful information. According to ESA’s Web site, Philae should be landing as I’m posting this, but no word yet.

There have been times when APOD missed major events and was then criticized for not featuring an image from said event. But never have I seen it compared to CNN!

[Chris Peterson]

I’m tempted to remark that APOD has fallen for CNN Syndrome: “We Bring You the News Before It Happens.”

But the Philae landing attempt actually was news even before the landing itself. So today, a graphic telling us what to expect, and hopefully tomorrow, an image from the surface of a comet.

[JohnD]

Philae - pronounced "fee-lie", if you ever did Latin at school.

A triumph for the European Space Agency, and world science!
JOhn

[Ron-Astro Pharmacist]

A newspaper report I read yesterday quoted someone from the team estimating a 50% chance of successful landing, which should be considered as "icing on the cake", since 80% of the science program has been, or will be done by the orbiting Rosetta. Well, I think I can speak for most icing lovers with a "bonne chance" to the team. (No pressure.)

"Today’s successful landing is undoubtedly the cherry on the icing of a 4 km-wide cake"

Hey Nit – You got your icing and a cherry to boot. Just need some candles. No need to blow them out because I think everyone at ESA already got their wish. The presents are coming soon. Fun days ahead for us thanks to more effort than we can imagine. Nice Job for a 10 year old+ Philly!

13064352255_51a94a1811_m.jpg (20.98 KiB) Viewed 135915 times

Now if you will just stay in the corral.

[geckzilla]

So far it looks like Philae bounced at least twice. I guess the spears either didn't fire or didn't take hold? Either way, good to hear it didn't go flying off into the abyss. Still, if it's not held down, I wonder if the drill will work.

[Nitpicker]

Does anyone happen to know the current orbital period of Rosetta, or even better, the periodic intervals of radio communication and radio blackout with Philae, due to Rosetta's orbit?

[DavidGovett]

No videos?
BTW, I remember when America had a space exploration program. So long ago.

[Nitpicker]

No videos?
BTW, I remember when America had a space exploration program. So long ago.

Well, you should try playing "count the American missions" on this page:
http://en.wikipedia.org/wiki/List_of_ac ... tem_probes

[alter-ego]

So far it looks like Philae bounced at least twice. I guess the spears either didn't fire or didn't take hold? Either way, good to hear it didn't go flying off into the abyss. Still, if it's not held down, I wonder if the drill will work.

Yeah, and in this article Philae may have gone aloft for another 2 hours! It will be interesting to see how far away it is from the planned landing site. The "top" of the comet's small lobe (site J planned landing location) is also the rotational plane. I assume the approach trajectory is in the direction of rotation which would likely minimize the actual landing site error after a bounce. Otherwise the landing position error could be large (worst case ~2km assuming ~0.3m/s surface velocity x 2 hours aloft time).

[Nitpicker]

Does anyone happen to know the current orbital period of Rosetta, or even better, the periodic intervals of radio communication and radio blackout with Philae, due to Rosetta's orbit?

I suppose Rosetta's orbital period is not that important, since the comet rotates with a period of 12.4 hours. Silly me.