If anyone tells you the Earth isn’t warming up…

… tell them they’re full of it.

2011 was the ninth hottest year on record, and those records go back 130 years.

And then they might say, well, sure, but that could be coincidence. Then you look them straight in the eye, and you say:

Nine of the ten hottest years on record have been since 2000.

The map above shows changes from average (where the average is from 1951 to 1980). You see clearly that temperatures over land have increased almost universally. Most of the ocean temperatures have gone up as well; the one big cooler region in the eastern Pacific is due to the La Niña last year, so it’s a temporary effect. Even with La Niña dropping temperatures, the overall effect is an increase in temperature. I’ll note that sunspot numbers were low last year as well, which (if anything) should result in a (very) slight cooling effect too.

Climate change deniers will gnash and froth — I expect the comments to this post to reflect that, as they always do — but the bottom line is this. The Earth is getting hotter. Human beings are at least partly to blame, and the evidence has piled up that we are mostly to blame. Not the Sun, not cosmic rays, not orbital oscillations. Humans.

As I’ve said before, here are the facts:

The Earth is warming up. The rate of warming has increased in the past century or so. This corresponds to the time of the Industrial Revolution, when we started dumping greenhouse gases into the atmosphere. Greenhouse gases warm the planet (hence the name) — if they didn’t we’d have an average temperature below the freezing point of water. Carbon dioxide is a greenhouse gas which is dumped into the atmosphere by humans to the tune of 30 billion tons per year, 100 times the amount from volcanoes. And finally, approximately 97% of climatologists who actually study climate agree that global warming is real, and caused by humans.

Given the vast amount of evidence supporting all this, denying it is fantasy. Again, that won’t stop deniers: they will obfuscate, blow smoke, and nitpick details to make them seem important. But what they’re doing is fiddling while Earth burns.

NASA’s Earth Observatory site just put up this amazing picture. I have to say, this is one of the cooler pictures from the International Space Station that I’ve seen. Not for it’s beauty or anything like that — though it is starkly lovely — but because of what it shows:

[Click to dicraternate.]

Obviously, that’s a volcano on the right: Emi Koussi, in northern Africa. But look to the left, almost at the edge of the picture. See that faded ring? That’s Aorounga — an impact crater, some 10 – 15 km wide, formed when a chunk of cosmic debris hit the Earth about 300 million years ago! So these are two craters, one formed from processes happening deep below the Earth, and one from events from far above. Yet both can be seen at the same time, from one vantage point: orbiting our planet somewhere above the surface but beneath the rest of the Universe.

Image credit: NASA

Yesterday, I was in a live video chat session with several other scientists and science journalists. I wrote up the details of it yesterday, and it went pretty well! We had a lot of fun talking about the new GRAIL Moon mission, the fiery future return of Phobos-Grunt, 2012, and of course President Obama’s purported teleportation trip to Mars many years ago.

Wait, what?

Well, if you wanna know more, now you can: the video’s online.

The plan is to do these every week on Thursdays, and have a rotating cast of characters over time. I hope you like it. And I strongly suggest people join up over at Google+. I really like it there, and post quite a few things you won’t see here or on Twitter.

Fraser Cain (from Universe Today) and I are trying something new… and by new, I mean new. We’re going to be holding a live video weekly astronomy and space roundup on Google+! We’ll have a roundtable group of scientists and science journalists discussing the latest cosmic news, explaining it, and letting you know what it all means. We have a pretty good group of folks lined up for this, and the first one will be held today, Thursday, January 5 at 18:00 UTC (1:00 p.m. Eastern US time).

[UPDATE: We're live now!]

These will be held on Google+ using Hangouts on Air – a live video stream that can be watched by an unlimited number of people. You have to be on Google+, and then circle Fraser Cain — that’s G+’s version of adding friends. He’ll have the link to the video feed in his stream once it’s set up (and I’ll update this very blog post as well). And once you’re in, you can ask questions for us in the comments section on the post! You can read more about this on Universe Today.

I’m very excited about these live video news session. For one thing, we’ve done this a few times already in a rather impromptu way, and it’s worked out really well. We can talk about news, switch from one person to another, and take questions from people watching. It’s all live and real-time — yesterday, we even had a live feed from a telescope in Bucharest where we observed the Moon! That was amazing.

Also, Google+ is turning out to be a really cool place to be, with a lot of very intelligent and thoughtful participants. It is not Facebook, with endless announcements of games, ads, and such. It’s far more of a discussion and an exchange of ideas. The addition of live video conferencing is a huge benefit too. Fraser and I think that this will change a big chunk of the internet… and maybe more. If you’re on G+ please circle me, and if you’re not, you’re missing out.

We have big, big plans. Just you wait.

But until then, I hope to see you on G+ for our roundup!

Mynd you, Møøn bites Kan be pretti nasti…

Today, NASA successfully put a new mission into lunar orbit: GRAIL, for Gravity Recovery and Interior Laboratory. Great acronym, weird name, right? What this mission will do is map the gravity field of the Moon, and use that to probe the interior composition. The basic idea isn’t all that complicated: fly a probe around the Moon. If it goes above a region where the density is higher, there will be a slightly stronger gravitational pull, and the spacecraft will accelerate a bit. By carefully measuring the spacecraft position and velocity, you can make the lunar gravity map.

In detail, that’s a bit tougher! What NASA has done is launch two probes, GRAIL-A and GRAIL-B, that will fly in the same orbit, one behind the other^*. They’ll stay in constant communication, sending radio pulses to each other. The timing of these pulses allows an extremely accurate determination of their separation: their distance will be known to an accuracy of about a micron: that’s a hundredth the width of a human hair, or the size of a red blood cell!

So how does that help? If one of the two probes speeds up or slows down, the radio signal timing will change, taking more or less time to get from one probe to the other. The amount of change is related to the force of gravity felt by the probe, and that in turn is related to the density of the material below. In practice, making a gravity map this way is extremely complex, but it’s been done before here at Earth using probes like GRACE and GOCE. It’s tried and true.

(more…)

When Expedition 29 astronauts Mike Fossum, Sergei Volkov, and Satoshi Furukawa returned to Earth from the ISS on November 21, Dan Burbank stayed aboard the station and got this dramatic picture of them coming home:

[Click to deorbitenate.]

See it? The returning Soyuz capsule itself is the bright dot in the center of the picture, and you can see the trail of plasma behind it, pointing almost straight down. It’s almost lost against the city lights below it.

I couldn’t find this picture on NASA’s Gateway to Astronaut Photography, unfortunately, but a little sleuthing gleans some info anyway. (more…)

Neil deGrasse Tyson may be the most recognizable astronomer on Earth these days, in part due to his frequent appearances on The Colbert Report. Earlier this year In 2010, Colbert sat down with Neil at the Kimberley Academy in Montclair, New Jersey and chatted with him about life, the Universe, and everything. Colbert did this out of his TV character — well, mostly — and even though it’s over an hour, it’s well worth your time. The original video is on the Hayden Planetarium site, but it’s also all over the place, including YouTube. I’ve embedded it here for your enjoyment, too.

Neil and I agree on a wide variety of topics, and he’s doing a great job inspiring people to look beyond their own immediate surroundings.