Philae on 67P/Churyumov-Gerasimenko: Kudos!

(From European Space Agency, used w/o permission.)
(ESA's European Space Operations Centre (ESOC) in Darmstadt, as Philae lander touched down on 67P/Churyumov-Gerasimenko. (November 12, 2014))

Those humans had good reason for being cheerful. They were at the European Space Operations Centre in Darmstadt, Germany — and were getting 'I'm here' signals from their Philea lander.

Kudos, humanity: one of your robots landed on a comet. Granted — Philae bounced a few times, fetched up, maybe on its on its side, and definitely not where it should be — but it's working, sending back data, and may have enough power in its battery to last until tomorrow afternoon. Maybe longer.

It could have been a lot worse: and is pretty good for a first try.

"...The Key Issue Vexing Controllers..."

(From European Space Agency, via BBC News, used w/o permission.)
("Some radio data suggests the probe may be about 1km from the intended landing site"
(BBC News))

"Rosetta: Battery will limit life of Philae comet lander"
Jonathan Amos, BBC News (November 13, 2014)

"After a historic but awkward comet landing, the robot probe Philae is now stable and sending pictures - but there are concerns about its battery life.

"The lander bounced twice, initially about 1km back out into space, before settling in the shadow of a cliff, 1km from its intended target site.

"It may now be problematic to get enough sunlight to charge its battery systems....

"...Telemetry indicates it is on a slope or perhaps even on its side.

"Certainly, one of its three feet is not in contact with the surface.

"The key issue vexing controllers right now is the lighting conditions.

"Philae is receiving about 1.5 hours of illumination during every 12-hour rotation of the comet.

"This will be insufficient to top up its battery system once the primary charge it had on leaving Rosetta runs out. That was some 60-plus hours...."

The Lemming appreciates that phrase: "...the key issue vexing controllers...."

To "vex" is "to annoy, as with petty importunities."

Sure, Philae may not last as long as mission planners hoped: but it landed, is in one piece, and still on speaking terms with its orbiter. This is pretty much good news.

From what the Lemming's read, nine of 10 experiment packages Philae carries are in good shape: and scientists may even get a chance to use the lander's drill.

Besides, what is it you humans say? "Any landing you walk away from is a good one." Philae has "legs," but couldn't walk anyway: the point is that this robot landed.

Philae didn't crash. It's still got power, and mission planners have most of a day before the batteries run out. Maybe engineers will get the robot right-side-up and in full sunlight before then. Even if they don't, right now it looks like the Rosetta lander will get some serious science done before it's done.

Optimists, Pessimists, and the Lemming

Someone said that an optimist sees a glass that's half-full, a pessimist sees one that's half-empty, and an engineer sees one that's twice as big as it needs to be.

From the Lemming's viewpoint, some news about Philae's landing was written by pessimists who see the glass as half-empty and leaking. Not that BBC piece. Jonathan Amos did okay.

And of course there's the usual kvetching about how many resources were 'wasted' on the Rosetta mission, instead of being spent on the reporter's — or, more likely, editor's — pet peeve.

The Lemming thinks you humans deserve a Lemming's 'thumbs up' for a job well-done, on the Rosetta mission so far. There's more to life than landing on comets, of course: but you've got brains, and in this case you used them.

Slightly-related posts:

• "Robird: False Falcons, Ersatz Eagles, and a Rambling Lemming"
  (September 5, 2014)
• " 'Tampering With Things Man Was Not Supposed to Know:' the Angst Continues"
  (August 1, 2014)
• "The Alchemist Trap"
  (March 14, 2014)
• "Voyager 1: Outward Bound"
  (January 10, 2014)
• " 'Young' Martian Mudstone: Only 80,000,000 Years Old"
  (December 12, 2013)

Tempel 1 / Stardust-NExT Flyby: How2 Watch Online

"5 Valentine's Day Facts About NASA's Comet Tempel 1 Flyby"
Space.com (February 14, 2011)

"NASA's Stardust spacecraft will zip close by the comet Tempel 1 tonight (Feb. 14) in a cosmic Valentine's Day rendezvous to take a new look at the icy wanderer.

"The cosmic flyby will mark the second comet visited by the Stardust spacecraft – as part of its extended Stardust-NExT mission – as well as the second time an unmanned probe from Earth has approached Tempel 1.

"In 2005, NASA's Deep Impact mission visited comet Tempel 1 and intentionally crashed a probe into the comet to determine its composition. Researchers hope tonight's Stardust flyby will give scientists a fresh look at the damage inflicted by the Deep Impact crash...."

The rest of the article is a sort of Valentines-Day-themed list of interesting facts about the Tempel 1 mission.

How to Watch the Tempel 1 Flyby Online

"Want to Watch NASA's Comet Tempel 1 Flyby? Here's How"
Space.com (February 14, 2011)

"NASA's Stardust spacecraft may be 209 million miles from Earth when it snuggles up to comet Tempel 1 tonight (Feb. 14), but that doesn't mean the rest of us will have to miss out. NASA is giving the public several ways to see the comet flyby online.

"First, a bit of cosmic scheduling info: The Stardust spacecraft will fly by comet Tempel 1 tonight at 11:37 p.m. EST (8:37 p.m. PST, 0437 Feb. 15 GMT). That's the time of closest approach, though cameras on Stardust have already been able to spot comet Tempel 1. The flyby is part of NASA's Stardust-NExT flight, which extended the Stardust probe's original mission after it visited the comet Wild 2 in 2004.

"How to watch Stardust-NExT's comet rendezvous:

"NASA will broadcast the flyby live on NASA TV starting at 11:30 p.m. EST. If you don't get NASA TV on your televisions at home, you can watch the webcast here: here: http://www.nasa.gov/ntv...."

Hey! What are you still doing, reading this post? If you're interested in the Tempel 1 / Stardust-NExT flyby - follow that link.

Or, if the flyby's already happened by the time you read this, you can try these:

• "Stardust-Next & Comet Tempel 1"
  NASA
• "The Two Faces of Tempel 1"
  NASA (February 9, 2011)

Comets: Looks Like They May Not All be From Around Here.

"Wanted for Theft: Sun Stole Its Comets From Other Stars"
Nola Redd, Space.com (November 23, 2010)

"It turns out our sun may be a cosmic thief that's stolen most of its comets from other stars, a new study suggests.

"Comets are small icy bodies that flare up when they near the sun as solar radiation vaporizes their ice to create a glowing tail.

"New computer simulations of the billions of comets crisscrossing the solar system suggest that most of them originated beyond our local neighborhood, but got grabbed and pulled in by our sun's gravity later...."

Current models of how the Solar system formed give a pretty good explanation for where comets come from: There's good reason to think that they formed from the same cloud of gas and dust that our sun, Earth, and the other planets did.

Just one problem. Although the Oort cloud comets are too far away to detect - directly - so far - we've got a pretty good census for comets that swing in close to the sun. That's not the problem.

It's the numbers.

They don't add up.

Back to the article:

"...[Southwest Research Institute, Boulder, Colorado's Hal] Levison and his team say there seem to be around 400 billion comets hovering just beyond Pluto. In comparison, the conventional model predicts only 6 billion.

" 'That's...a huge discrepancy,' Levison said. 'Too huge to be explained by mistakes in the estimates. There's no way we could be that far off, so there has to be something wrong with the model itself.'..."

Assuming that comets - some of them, anyway - came from the neighborhood of other stars helps explain the number of comets we see. It also explains the orbits of quite a few long-period comets: which can go far into the depths of space.

That means that we may be able to get samples of material from other stars a whole lot sooner than however long it takes to build really fast starships.

"...Comets are generally regarded as excellent snapshots of the early solar system, because they spend much of their lives encased in ice. But if some of these comets come from outside our solar system, then they can tell us about their parent stars, as well.

" 'We can study the orbits of comets and put their chemistry into the context of where and around which star they formed,' Levison said. 'It's intriguing to think we got some of our "stuff" from distant stars. We're kin.' "

Intriguing: and somewhat 'old news,' too. Our current models for how the universe works say that everything we're made of, apart from hydrogen, and maybe helium, was made in the cores of very old, very massive, stars.

And that's another topic.

Related posts:

• "A Serious Search for Other Worlds, Life, and - Maybe - Extra-Terrestrial Intelligence"

Hartley 2: First Photo of Maybe 64,000

"Comet-Bound Spacecraft Beams Back First Photo of Icy Target"
Space.com (September 21, 2010)

"A NASA comet probe has beamed back to Earth its first photo of its quarry, Comet Hartley 2.

"NASA's Deep Impact spacecraft is zooming toward the comet, snapping pictures in the lead-up to a planned flyby of the ice ball on Nov. 4. The new photo is the first of 64,000 or so the probe is expected to take of Hartley 2.

" 'Like any tourist who can't wait to get to a destination, we have already begun taking pictures of our comet, Hartley 2,' Tim Larson, the mission's project manager at NASA's Jet Propulsion Laboratory, said in a statement. 'We have to wait for Nov. 4 to get the close-up pictures of the cometary nucleus, but these approach images should keep the science team busy for quite some time as well.'..."

The photo itself isn't as stunning as the new Hubble image. There's a lot of bright spots that are stars and a biggish bright spot that's Hartley 2. That, and some lines and letters are about it.

Still - that's a comet, photographed by a robot spaceship that's set to take thousands more photos.

'Deep Impact?' Where's the Impact?

There's a pretty good explanation for the spaceship that's doing a flyby of Hartley 2 being called "Deep Impact." The craft's original mission was being the mother ship for the 2005 Deep Impact mission to Comet Tempel 1. After that mission, the mother ship was still in good operating condition: so NASA set it off on another comet-related mission, this time to Hartley 2.

Leonid Shower Tuesday and Wednesday Mornings

"Strong Leonid Meteor Shower Peaks Early Tuesday Morning "
Space.com (November 16, 2009)

"One of the best annual meteor showers will peak in the pre-dawn hours Tuesday, and for some skywatchers the show could be quite impressive.

"The best seats are in Asia, but North American observers should be treated to an above average performance of the Leonid meteor shower, weather permitting. The trick for all observers is to head outside in the wee hours of the morning – between 1 a.m. and dawn – regardless where you live.

"The Leonids put on a solid show every year, if skies are clear and moonlight does not interfere. This year the moon is near its new phase, and not a factor. For anyone in the Northern Hemisphere with dark skies, away from urban and suburban lighting, the show should be worth getting up early to see.

" 'We're predicting 20 to 30 meteors per hour over the Americas, and as many as 200 to 300 per hour over Asia,' said Bill Cooke of NASA's Meteoroid Environment Office. Other astronomers who work in the nascent field of meteor shower prediction have put out similar forecasts...."

"...The planet will pass through an even denser stream later, just before dawn Wednesday in Indonesia and China, but that show won't be visible from North America because it will be daytime here...."

The article tells where the Leonid meteors come from - the comet Tempel-Tuttle - and why they're called "Leonid" meteors.

North Americans get a look at Earth's passage through one of the dense streams around 4:00 a.m., Eastern time.

There's a pretty good collection of information here: background on meteors, on the Leonids in particular, and practical advice on how to watch for meteors.

Jupiter Imact: Hubble Took a Look

"Hubble Telescope Photographs Jupiter Impact Site"
Space.com (July 24, 2009)

"The unexpected impact of some space object with Jupiter, creating a dark bruise in the gas giant's atmosphere, proved a tempting enough target for scientists to put a hold on testing out the revamped Hubble Space Telescope and use its new camera to capture an image of the rare event.

"The plan, first reported by Spaceflight Now, was carried out yesterday so that astronomers could use the 19-year-old Hubble's unique capabilities to get an image of the spot, probably caused by a comet, before too many days had passed since the impact and Jupiter's atmosphere distorted the shape.

"The new Hubble image, released today, [Friday] shows a lumpiness to the debris plume caused by turbulence in Jupiter's atmosphere. The image is a natural color image of Jupiter in visible light...."

The dark patch is roughly the size of the Pacific Ocean, it seems. Which is pretty close to the headline I mentioned in an earlier post, saying that the hole in Jupiter's clouds was the size of Earth. Seen from space, the Pacific Ocean covers most of one side of this planet.

Why use Hubble? It gives the best, sharpest, look at Jupiter in visible wavelengths of any available telescope. "...Hubble managers decided that the impact event was rare enough and important enough to pause testing to get a look...."

This article gives a pretty good overview of what Hubble's observed, and what we know about the event on Jupiter. For one thing, the energy released in the impact was thousands of times more than what we experienced in the Tunguska event, back in 1908.

I've written before, about the prudence of setting up defenses before something leaves an ocean-size splat-mark on Earth.

Meanwhile, there's a lot to learn from that impact on Jupiter.

Related posts:

• "Big Impact on Jupiter: Astronomers' Field Day"
  (July 21, 2009)
• "Life Could Have Survived Earth's Late Heavy Bombardment"
  (May 24, 2009)
• "It Seems it Took More Than an Asteroid Hit to Finish the Dinosaurs"
  (April 29, 2009)
• "Asteroid Threat: Good News, We Have the Technology; Bad News -"
  (April 28, 2009)
• "Earth Day 2009: Don't Stop Breathing to Save Earth"
  (April 22, 2009)
• "Ten Not-So-Trivial Facts About Earth"
  (February 16, 2009)
• "How to Destroy Earth (It Ain't Gonna be Easy)"
  (July 9, 2008)
• "No Magnetic Field (to Speak of) For Mars: Asteroid Implicated"
  (May 12, 2009)

Big Impact on Jupiter: Astronomers' Field Day

"Jupiter Apparently Smacked by Rogue Object, New Images Reveal "
Space.com (July 20, 2009)

"Jupiter has apparently been smacked again by a rogue object hurtling through space, new images from amateur astronomers and NASA reveal.

"A giant scar-like blemish has appeared in the clouds near Jupiter's south polar region, which NASA observed in infrared after receiving a tip from an amateur skywatcher in Australia. The likely impact appears to have occurred exactly 15 years after the remnants of Comet Shoemaker-Levy 9 bombarded the planet in 1994 in an event that was widely predicted and scrutinized as it happened.

"The latest impact was not predicted, and it was caught by chance...."

The impact was discovered by an Australian amateur astronomer, Anthony Wesley, 44, who makes a living as a computer programmer. Situations like this, where an amateur astronomer is the first to notice a new phenomenon, aren't all that rare. Professional astronomers are paid to use their very expensive installations to watch places that are known to have valuable data. It's the amateurs who are everywhere else, ready to notice when something unexpected shows up.

Anthony Wesley almost missed this impact.

"...In an observation report posted to his Web site, Wesley said he almost missed spotting Jupiter's new blemish entirely because he was tired after a late-night skywatching session.

" 'It was a very near thing,' he wrote, adding that by 1 a.m. Local Time, he decided at the last minute to keep observing for another half hour.

" 'I'd noticed a dark spot rotating into view in Jupiter's south polar region and was starting to get curious,' Wesley went on. 'When first seen close to the limb (and in poor conditions) it was only a vaguely dark spot, I thought likely to be just a normal dark polar storm. However as it rotated further into view, and the conditions also improved, I suddenly realized that it wasn't just dark, it was black in all channels, meaning it was truly a black spot.'..." (Space.com)

The Space.com article is one of the first to take note of the July 19, 2009, impact on Jupiter. I've put links to several of the more recent articles toward the end of this post. The Space.com article is more detailed than many - although Today's CNN article does a pretty good job of passing details along.

A Bunch of Astronomers Looking at Jupiter: So What?

It's been 15 years since Comet Shoemaker-Levy 9 hit Jupiter. That was a scientific bonanza: since the comet had been tracked before impact, and the time and place of the impact was predicted, astronomers had a chance to set up an impressive array of sensors to record the event.

And, since it happened on Jupiter, the effect on Earth was somewhere between negligible and non-existent - as far as we know.

This impact was on Jupiter, again, but it wasn't predicted. Mr. Wesley didn't know he'd be giving the heads-up to professional astronomers a couple days ago.

Big Impact of Jupiter: Fascinating, but Not Earth-Shattering

Having the second big impact in 15 years happen on Jupiter isn't such a surprise. Jupiter is the biggest planet, in terms of diameter - and is vastly heavier than anything else in the Solar System except for the sun. Decades ago, someone referred to the planetary system we're in as being 'the sun, Jupiter, and debris.'

So, between being a big target and having a whacking great gravitational field to pull assorted rocks and ice balls in, being fairly close to the asteroid belt, and having an orbit that comets sometimes cross on their way to the sun, Jupiter is going to have big, heavy things falling on it fairly often.

What's a little disturbing about this latest impact is it wasn't predicted. Nobody noticed something approaching Jupiter before an Earth-size hole was blasted in the upper cloud decks.

Asteroid Impact Here? Still Not Earth-Shattering - But We Wouldn't Like it

I don't know enough physics to say what sort of energy is needed to punch a hole thousands of miles wide in Jupiter's upper cloud layers: but my guess is that I wouldn't want to be anywhere nearby when energy on that scale is released.

And, since Earth is only about 8,000 miles across, if something like what hit Jupiter last Sunday came down in, say, Antarctica, anywhere on Earth would be "nearby."

An event like that would push news about floods in Mongolia off the front page. It would probably even eclipse coverage of Michael Jackson's death. And, humanity would have a great deal more to worry about than getting ready for the Olympic Games next year.

I'd rather not find out whether or not there would be people around, ten thousand years after such an impact. Cockroaches, though, almost certainly would be. They've been through quote a few hard times on Earth.

We Have the Technology to Protect Ourselves

I was mildly surprised to discover that The Spaceguard Foundation was organized in 1996. I'd expected to find an earlier founding date. Serious discussions among and loose associations of astronomers concerned with tracking objects that might hit Earth go back decades.

We've got the technology to detect (most) largish objects that might hit Earth, track their orbits, and make pretty-good estimates of when and where they might hit. As they got closer, we'd be able to make increasingly accurate predictions.

We've also got the technology to do something about a big rock, or gravel pile, or slushball, headed our way. The relative merits of moving the incoming object so that it misses Earth, or breaking it up so that it hits, but in small pieces over a large area, have been discussed.

The 'breaking it up' scenario isn't, necessarily, as crazy as it may sound. Earth gets hit by around 2,000 tons of meteor every day. (Journal of the Royal Astronomical Society of Canada, via Harvard) Except for a few astronomers, we don't notice all those tons of stuff falling on our heads, because most of it burns up in the upper atmosphere.

My guess is that adding more tonnage would make a measurable difference, somehow. And, that it would result in a spectacular one-time-only meteor shower. And, in America, several thousand lawsuits for everything from emotional suffering to a disappointing vacation.

Earth and Asteroids: We've Been Lucky, So Far

I'd like to think that outfits like The Spaceguard Foundation will distract national leaders from whatever it is that they usually do long enough to get an effective detection and interdiction force in place. Before something like the Tunguska Event happens over someplace like Singapore or Dallas.

Related posts:

• "Life Could Have Survived Earth's Late Heavy Bombardment"
  (May 24, 2009)
• "It Seems it Took More Than an Asteroid Hit to Finish the Dinosaurs"
  (April 29, 2009)
• "Asteroid Threat: Good News, We Have the Technology; Bad News -"
  (April 28, 2009)
• "Earth Day 2009: Don't Stop Breathing to Save Earth"
  (April 22, 2009)
• "Ten Not-So-Trivial Facts About Earth"
  (February 16, 2009)
• "How to Destroy Earth (It Ain't Gonna be Easy)"
  (July 9, 2008)
• "No Magnetic Field (to Speak of) For Mars: Asteroid Implicated"
  (May 12, 2009)

In the news:

• "Mystery impact leaves Earth-size mark on Jupiter"
  CNN (July 21, 2009)
• "Jupiter 'struck by large object' "
  BCC (July 21, 2009)
• "Jupiter Struck by Object, NASA Images Confirm"
  Reuters, Via FOXNews (July 21, 2009)

Background:

• The Spaceguard Foundation
  Nec cum fiducia inveniendi
  Nec sine spe
  • This is the mirror site hosted by Harvard. There are at least two others, in
    • Europe (Italy)
    • Japan
• "Meteor News (A Size Classification of Meteoritic Material Encountered by the Earth)"
  Millman, P. M., Journal of the Royal Astronomical Society of Canada, Vol. 46, p.79, via Harvard

Now, That's a Big Comet

"Comet Holmes Bigger Than The Sun"

It's supposed to have been a naked-eye object, in the northwestern sky. Between weather and schedules, I haven't had a chance to take a look.