Tag: Comet

Everything Had To Go Right… And Didn’t

The probe has come to rest alongside a large boulder. It is blocked from the Sun. Its solar cells, hoping for eight hours of daylight, only get one and a half.

Philae will work for a few days, then run out of juice.

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I am heavily invested in Rosetta and Philae, the orbiter/lander combo at Comet 67/P. It was the focus of my recent trip to NASA JPL and our recent show on Slooh.com. I did lots of show prep.

Everything went right with Philae until it didn’t. It’s ending will deprive science of much of the data they’d hoped for.

Philae was released by Rosetta and dropped toward the comet. The word ESA used was “ballistic.” With nearly zero gravity the 200’ish pound Philae weighed around a gram. The drop took seven hours.

It hit the comet’s surface at walking speed, but the ice screws didn’t grip and its harpoons didn’t deploy.

The harpoons did not fire and Philae appeared to be rotating after the first touchdown, which indicated that it had lifted from the surface again.

Stephan Ulamec, Philae manager at the DLR German Aerospace Center, reported that it touched the surface at 15:34, 17:25 and 17:32 GMT (comet time – it takes over 28 minutes for the signal to reach Earth, via Rosetta). The information was provided by several of the scientific instruments, including the ROMAP magnetic field analyser, the MUPUS thermal mapper, and the sensors in the landing gear that were pushed in on the first impact.

The first touchdown was inside the predicted landing ellipse, confirmed using the lander’s downwards-looking ROLIS descent camera in combination with the orbiter’s OSIRIS images to match features.

But then the lander lifted from the surface again – for 1 hour 50 minutes. During that time, it travelled about 1 km at a speed of 38 cm/s. It then made a smaller second hop, travelling at about 3 cm/s, and landing in its final resting place seven minutes later. ESA news release

The probe has come to rest alongside a large boulder. It is blocked from the Sun. Its solar cells, hoping for eight hours of daylight, only get one and a half.

Philae will work for a few days, then run out of juice. It’s a lander, not a rover.

In the meantime there’s concern deploying some of its instruments could bounce Philae again. No one knows where. At the moment even scientists aren’t even sure where on the comet Philae sits.

There will be good science from this mission, but not as much as hoped for. Space continues to be a supremely challenging pursuit. It is still much too dangerous and expensive to include humans. It always will be that way.

I’m Studying Up On Mars

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Tomorrow will be busy for me. We’ve got two slooh.com shows about the close encounter between Comet Siding Spring and Mars.

I host, surrounded by cometary experts. I still have to know the science.

This is an unprecedented event. We’ve never seen a comet get so close to a planet.

That worries NASA.

Actually, let me modify that. Their worry is later.

First, cards on the table. NASA is always interested in ‘visitors’ to our part of the solar system. But there’s a lot more buzz for Comet Siding Spring C/2013 A1. It will come close to Mars and to billions of dollars of hardware circling Mars, plus rovers on-the-ground.

Comet-Siding-Spring-Trajectory-Mars-br2Siding Spring is speeding in from the Oort Cloud, a theorized mass of billions of comets 100,000 times farther from the Sun than we are. It will zip by Mars at a closing speed 35 miles per second–186,000 mph.

The comet misses Mars. We’ve all got that, right?

Later, Mars passes through the debris field left in the comet’s wake. Scientists expect some fragments will be drawn toward the planet where we have satellites and stuff.

NASA’s official “Best Estimate” says the particles miss. Their conservative estimate says 90-100 minutes after the closest approach a stream of small debris will come, then quickly go.

Our satellites all had their orbits disrupted, putting them on the far side of Mars when this happens.

T-0 is officially called the “time of the particle fluence center.”

NASA is praying one or more of the rovers will take a photo or two of the comet brightly shining through the Martian atmosphere. That’s pretty damn cool. It will likely happen and will surely include a part of the rover, lest we forget whodunit.

We’ll also get images from whatever sensors can be turned around on satellites.

I’m not sure how much of this is actually advancing science and how much is showing off. An opportunity and challenge like this shouldn’t be squandered, but this is more photo-op than anything. After all, we’re landing on a comet next month!

Everything is now set. It’s too late for change to matter. Any debris that hits the Red Planet was jettisoned off the comet years ago.

Distance and time are very different in space. You can’t think in minutes and seconds or inches and feet. Our best orbital predictions say C/2013 A1 won’t be back for around a million years.

Rosetta Sounds Like A Movie Plot, But This Is Real

Where is Rosetta

Five hundred million kilometers from Earth a comet is streaking toward the Sun. No worries. Not a threat to us.

Earthlings, being curious people, thought we’d send a mission to this comet to find out what it’s made of. Theoretically, comets are a direct link to the universe just after the Big Bang.

Rosetta_mission_selfie_at_16_kmCatching a comet is no easy feat. Its speed is greatly affected by proximity to the Sun–so, constantly changing. Our comet is doing around 38,000 mph today. The instant we arrive we need to be doing exactly the same speed as the comet. Seriously, at that instant exactly.

To get to Comet 67P/CG “Rosetta” will travel over 6,500,000,000 kilometers. That’s on purpose. By swinging through the Earth’s gravitational field a few times engineers were able to stretch precious fuel.

Rosetta is now orbiting Comet 67P/CG at around 10 miles, a little higher than commercial jets fly.

Getting to the comet wasn’t enough. How about we land on it? It’s the 21st Century equivalent of climbing from your horse onto an out-of-control stagecoach!

Rosetta_OSIRIS_NAC_comet_67P_20140803_1The comet is weirdly shaped, moving and spinning. It’s sublimating ice, so we see gas jets spewing out. More than likely the comet’s path from moment-to-moment is irregular. There is nearly zero gravity to prevent a landing spacecraft from just bouncing right off.

November 12 a small instrument package will be jettisoned from Rosetta. Rockets pushing toward the surface will hold it in place as harpoons try to get a grip. “Philae” will set up shop for scientific experiments and transmit results to Rosetta which will relay it back to Earth.

I have no doubt this will work.

What NASA and the European Space Agency have done here is nothing short of incredible. It’s much more than most people imagine can be done today. I wish this kind of engineering heft was also available for some of the Earth’s seemingly insurmountable problems.

Now It Can Be Told: My Stuff For Slooh

As some of you may know, I’ve been doing some work for slooh.com. Slooh is an astronomy community. Its three telescopes are available to the members. Two of the scopes are in the Canary Islands. One is in Chile. Each is in a superb location to clearly view the nighttime sky.

My job is to produce videos and host webcasts for Slooh.

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As some of you may know, I’ve been doing some work for slooh.com. Slooh is an astronomy community. Its three telescopes are available to the members. Two of the scopes are in the Canary Islands. One is in Chile. Each is in a superb location to clearly view the nighttime sky.

My job is to produce videos and host webcasts for Slooh. We’ve got one coming up Friday at 6p EDT/3p PDT about Comet 209P/Linear. It’s the object responsible for what could be an amazing meteor shower Friday night.

Slooh has also just announced a partnership with NASA in their Grand Asteroid Challenge. I produced a 2 1/2 minute video for that (below).

Screenshot-2014-05-16-19.59.36If you would have stopped me when I got into broadcasting and told me I’d be able to edit something like this without leaving my home office I’d have thought you nuts! These capabilities are beyond amazing.

I designed this PC specifically for editing It’s equal to the task. I couldn’t be happier.

I’m pretty happy with how the video came out too.

Incredible Engineering: Rosetta Wakes Up

Comet_approach_node_full_imageNothing is impossible. I say that without fear of contradiction because of what the European Space Agency and NASA have been doing for the last decade. It’s the Rosetta mission.

Rosetta’s job is to monitor a comet, 67P/Churyumov-Gerasimenko, by placing an orbiter around it and a lander on it! It will do this as the comet races toward the inner Solar System.

Rosetta_trajectory_English[1]As you might imagine, catching a comet isn’t easy. Rosetta was launched in 2004 and has made three Earth passes, plus one trip around Mars, all to gain speed and set-up its rendezvous.

To conserve power while coasting through space, Rosetta’s been ‘sleeping.’ Here’s how they list it on the mission timeline.

July 2011 Aphelion/Enter Hibernation

Rosetta_approaching_its_ultimate_destination_Comet_67P_Churyumov-Gerasimenko_node_full_imageAphelion means its furthest point from the Sun. Hibernation… you get that.

Today Rosetta gets its wake-up call! It needs to start processing data. It needs to prepare for its May meet-up with Comet 67P/Churyumov-Gerasimenko.

This is another unbelievably complex and intricate engineering challenge that should be impossible. What could possibly be more difficult than this?

Comet Ison Taught Me A Lot

743538main_image001_0As a meteorologist on TV I was often called on to be a science generalist. From earthquakes to volcanoes to comets, I had to know enough get on the air and provide context. It was a part of the job I relished.

Comets appeared from time-to-time, allowing me to get some shaved ice and dirt and give a quick lesson. There are not many people who get the opportunity to teach science on TV. It was an honor.

What I knew would not have been enough for Comet Ison. This comet was unusual. I learned a lot.

Astronomers first caught sight of Ison in September 2012 when was 585 million miles away. Even at that distance it was bright enough to hint at big things ahead.

Automated spotting programs make comet discoveries easier. Computers look for objects that are moving while the rest of the star field stays relatively in place.

By October a paper delivered to the American Astronomical Society’s 45th Annual Division for Planetary Sciences meeting noted Comet Ison was rotating in such a way that only one side was getting heated by the Sun and it was already spurting water ice into space.

Comet Ison is/was a sungrazer. Sungrazer’s are comets which get close enough to the Sun to be intensely affected by its gravity and heat. We’d never spotted a sungrazer so far out. Probably from the Oort Cloud, this was Ison’s first trip to the rodeo.

Until Ison, all the comets I’d talked about stayed far enough away from the Sun and had ‘visited’ this part of the solar system often enough that they weren’t in peril. This one was headed inside the Roche limit.

The Roche limit, sometimes referred to as the Roche radius, is the distance within which a celestial body, held together only by its own gravity, will disintegrate due to a second celestial body’s tidal forces exceeding the first body’s gravitational self-attraction. – Wikipedia

So, if Ison was a mass of rocks, pebbles and dirt held together by ice and its own internal gravity, the Sun would probably break it apart. That’s what happened. If Ison was an asteroid or some other giant space boulder we’d probably be looking at it still. Whatever does exist today is a small fraction of its former self.

I know this now. I didn’t know this a week ago or when I was talking about much colder comets on TV.

We see comets and their signature tail because heat (usually not very much heat) allows ice to melt which in turn allows gases to vent and dust to be set free. A comet’s tail is blown by the solar wind, a field of energy blasted into space from the Sun. The tail points away from the Sun and has no relation to the direction the comet is actually moving.

If all the ice has melted and the nucleus disintegrated there’s nothing left to view. That seems to be the case. There will be no “Comet of the Century” in the December sky.

We’re very lucky it’s 2013. There are a few satellites, some far from Earth, specifically designed to monitor activity like this. They provided amazing images as Ison whipped its way around the Sun and back toward deep space.

Over the next few months, as astronomers and other specialists look at the tsunami of data produced, we’ll learn more. It’s likely we’ll find Ison’s exact makeup and what caused its demise. I wouldn’t be surprised to see some animations simulating Ison’s final interactions with the Sun.

This comet was a tease. We were told it could be the big one. Obviously, it was not.

It wasn’t a disappointment to me. My knowledge has expanded. I might have been a terrible student as a kid, but grown-up Geoff loves to learn.

Over the last few weeks I’ve heard a lot of those in the know compare comets to cats. The both have tails and they both do what they want to do.

Ciao, Ison.

Am I The Cometary Kiss Of Death?

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Earlier today I posted a really cool animation from the Stereo-A satellite which monitors the Sun. It showed Comet Ison and Comet Encke heading toward the Sun while being blasted by the solar wind.

Many people feel (or felt) Ison might be the brightest and easily visible comet of our lifetimes! Almost as soon as I posted to my blog new information began to arrive suggesting hopes would be dashed.

We are seeing reports online that molecular emission from the comet has fallen dramatically, meanwhile dust production seems to be enormous. What this could indicate is that the nucleus has completely disrupted, releasing an enormous volume of dust while significantly reducing emission rates. Fragmentation or disruption of the nucleus has always been the highest risk factor for this comet so if this has indeed happened then while unfortunate, it would not be a surprise.

However, these reports are new, and while they are undoubtedly valid, we do still need to keep observing the comet to be sure what is happening. Karl Battams, Naval Research Laboratory

Simply put, it’s possible the comet has broken apart or disintegrated leaving a trail of dust and debris.

All along scientists hinted this was a possibility. Comet Ison has spent hundreds of thousands of years&#185 in the darkest reaches of space. It was safely removed from any source of heat, light or gravity. Now that was changing and changing in a hurry.

Today’s revelation is preliminary info. It points to a likely outcome, but that’s no guarantee. The more comets we see, the more we realize how little we know.

&#185 – It is being reported Comet Ison’s orbit arounnd the Sun takes 582,666 years!