The Evening Star

Just wanted to share this lovely photo I found of the Evening Star following the setting Sun down behind a distant dusky mountain range. The star's about halfway up the sky, one-third of the way from the left side. See it?

I expect you're thinking that's a pretty picture but nothing remarkable. You've probably seen a thousand sunsets like that yourself.

How mischievous of me not to mention that this sunset took place on Mars, and the Evening Star is us, photographed by the Curiosity rover.

Because Earth is closer to the Sun than Mars, Earth is an evening and morning star there, just as Venus and Mercury are to us. A Martian would never see the Earth directly overhead at midnight.

What elevates this photo beyond "Gee whiz!" all the way up to "Holy moley that's one of the best space photos I've ever seen!" is that if you download the full-resolution version here and take a real close look, you can see a simple truth we take for granted: we live on a double planet. This picture doesn't just capture the Earth, it shows our Moon.

Doing some quick math, I'm pretty sure you'd be able to see both with the naked eye. Earth had a magnitude of -1 (comparable to an extremely bright star like Sirius, or Venus or Jupiter from Earth) while the Moon's magnitude was about +2.7, same as a mediumish-bright star. (The magnitude scale is weird; it's both backwards and logarithmic. Negative numbers are brighter than positive numbers, and the limit of the naked eye is about Mag +6). The apparent separation of the Earth and Moon when this photo was taken was about as large as it gets, say 380,000 km, and JPL says we were 160 million km away, making the separation as seen from Mars about 8 arc-minutes. A full Moon as seen from Earth is about 30 arc-minutes across, so the Earth-Moon pair as seen from Mars is separated by a distance about equal to one-fourth the diameter of the Moon.

By way of comparison, the famous star pair Alcor and Mizar in the handle of the Big Dipper are about 12 arc-minutes apart, and Mizar's magnitude (+2.2) is similar to the Moon's in this photo. Alcor-Mizar are not difficult to see. Also keep in mind that the Earth and Mars are relatively far apart right now. Sometimes that 160 million km shrinks to one-third that distance.

Easy peasy!

Imagine what ancient Martian astronomers would have made of us, watching this pair of stars--the piercing blue one among the brightest objects in their sky--circle each other every 26½ days (Martian days just are a little longer than Earth days). Imagine the mythology they'd create to explain us. We'd be gods to them; maybe a parent and child? We would be the most awesome and mysterious thing in their heavens.

This is a view humans will get to enjoy someday. I envy them.

Newest Coolest Picture Ever, Apollo Edition

I periodically post pictures that I claim to be the coolest ever, most of which have something to do with space and a few of which come from the Lunar Reconnaissance Orbiter (LRO) currently free-falling around the Moon and mapping it with unprecedented precision. The latest Coolest Picture Ever is one of the latter.

Over time, as the LRO's orbit drops closer to the surface, its images get clearer and more detailed. Like this one, showing the landing site of Apollo 15 from just 15 miles (25 km) overhead (that link leads to higher-resolution versions):


Some of what you're looking at: In the center is the base of Apollo 15's Lunar Module "Falcon," the legs left behind when astronauts Jim Irwin and Dave Scott blasted off in the top half. I love the detail visible in the descent stage's shadow. The spot marked "ALSEP" is the Apollo Lunar Surface Experiments Package, while the "LRV" is the Lunar Roving Vehicle--the Moon dune buggy first used on this mission. And weaving around and among those features are the paths made by the astronauts' boots and Rover's tires, tracks that will endure on the Moon millions of years longer than anything humans have created on Earth.

I am simultaneously amazed that we can see those footprints four decades after they were made, and disappointed that we haven't been back to make new ones in the four decades since. But mostly amazed. That's so COOL!

In fact, it may be the Coolest Picture Ever.

Value-Added Bonus: here's the last time someone saw the Falcon's descent module from the surface, as transmitted by a video camera deliberately left running on the Rover. Just looking at the angles of where the LRV, ALSEP and descent stage are, I wonder if the white blob to the right rear of the descent stage is part of the ALSEP (it could also be a boulder, crater rim, or something else--distance is hard to judge on the Moon). If so, it's a two-fer! "Up we go into the wild blue yonder" indeed.



Appreciate this. It'll be a long time before anyone sees its like again.
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Return of the Coolest Picture Ever

It's been a while since I posted a "Coolest Picture Ever," but this one certainly qualifies. With the Space Shuttle program winding down (just one flight left), NASA seems to be taking every opportunity to capture spectacular beauty shots they never had time for before. If they'd released photos this sexy 25 years ago, we might have ourselves a real space program today.

There are a couple of interesting things happening in this picture. It's a fairly long time exposure taken while Endeavour was on the night side of the planet. The shuttle is illuminated by lights shining from within its own bay (and maybe some light from the International Space Station or backglow from the Earth itself?) while it zips over city lights a few hundred miles below. NASA astronauts don't take a lot of pictures at night for the same reason you and I don't: it's dark! But wow. What a beauty.

I've got to mention the stars. Most photos taken in space don't show any, which is one of the points of "evidence" cited by the Moon hoaxers who don't believe Apollo really went anywhere (as if NASA would've spent billions faking the Moon landings but forgotten to hang up a black curtain studded with Christmas lights). Those pictures don't show stars for, again, the same reason your nighttime snapshots don't. The camera exposure time is too short. Taking a photo of a white-suited Moonwalker or white-tiled spacecraft in direct sunlight requires about the same shutter speed and f-stop as shooting them on a sunny afternoon in the Mojave Desert would. Stars are thousands of times fainter and you've got to leave the shutter open a long time for anything to show up, meaning you have to hold very still--quite difficult on a spacecraft orbiting at 17,000 mph (in fact, if you zoom in on the high-resolution version of this shot on the NASA website, you can see the stars streaking just a little bit).

Thanks for your service, Endeavour. Maybe someday I'll get down to L.A. and visit you at the California Science Center. But it won't be the same.

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Coolest Photo of the Year

... so far. Courtesy of Bad Astronomer Phil Plait, whose blog is a regular stop of mine, comes this gorgeous image of the most recent full Moon shot in France by astrophotographer Thierry Legault:

So that's a nice enough pic of the Moon, I guess, but what elevates it to "Coolest Photo of the Year (so far)" status? Just that little dark blotch directly above the bright crater Tycho:


That's the International Space Station, whose orbit Legault researched and then set up his camera in the right place at the right time to capture the half-second it took the station to zip across the lunar disk. The station is about 250 miles (420 km) away, the Moon about 900 times that far. For comparison, here's a recent NASA photo of the ISS from space, which I've rotated to about the same orientation:


Look what we can do!
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I Can See My House From Here

Yours, too.

I've got a new candidate for "Coolest Picture Ever" today: an image shot by the Messenger space probe from 114 million miles away showing, at lower left, our Earth and Moon.

As NASA explains here, Messenger wasn't really aiming for us. We just happened to fall into its field of view as it searched for small asteroids in the neighborhood of Mercury, which it was sent to explore.

What I love about this picture is that it shows how we essentially live on a rare double planet. Our moon is unusually large in proportion to its mother planet (there are bigger moons in our solar system, but they accompany much bigger worlds). Being able to look up and see our satellite as a sphere with surface craters and mare, rather than a featureless bright light moving through the sky, is a rare gift we take for granted because we grew up here. And that's not even counting the fact that it has just the right orbit and size to perfectly eclipse the Sun, a one-in-a-jillion coincidence itself! If there were such a thing as alien tourists, they might travel halfway across the galaxy to see such a wonder. And its impossible to guess how different life on Earth would be--or if there'd even be life at all--without it.

The very best Best Pictures Ever remind us to look around once in a while and marvel.
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Return of the Coolest Picture Ever

It's been a while since I've seen a photo that took my breath away and deserved the title "Coolest Picture Ever." I got one today.

The European space probe Rosetta just flew within 2000 miles (3200 km) of the asteroid Lutetia, on its way to rendevous with comet Churyumov-Gerasimenko in 2014, shooting pictures coming and going. Most of them are swell pics of a never-before-seen asteroid left over from the formation of our solar system. I'm sure scientists will learn much from them, but these days they're pretty routine. Then there was this one:


That's Lutetia in the foreground and the planet Saturn far in the background. Holy cow! I don't think most people who went through school thinking of the solar system as a styrofoam-ball mobile hanging from the classroom ceiling have a feel for how relatively small the planets are, the enormous distances between them, or how much nothing there is out there. The idea that for a few seconds Rosetta, Lutetia, and Saturn were near enough to each other and lined up just right to get this shot astounds me.

In WHTTWOT I wrote about Mariner 4, the first successful probe to take close-up photos of another planet (Mars) in 1965. Until then, the best pictures in existence of anything farther away than the Moon were blurry blotches from ground-based telescopes. Now, probes like Rosetta are dully routine. We're orbiting Saturn, heading into interstellar space, flying past asteroids, landing on comets. All in my lifetime.

Any picture that can make me stop and reflect on that is the Coolest Picture Ever.

More at The Planetary Society and Phil Plait's Bad Astronomy blog.
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Coolest Picture Ever: The Conspiracy Deepens

My new best friend Jim O'Kane brings us the latest Coolest Picture Ever, a continuing series of photos I post--mostly of space stuff--that make the voice in my head exclaim "Holy Moley!" (because the voice in my head thinks in a pastiche of 1940s comic book slang).

I believe this is the second time I've posted images from the Lunar Reconnaissance Orbiter (LRO), a probe that's been circling the Moon for months shooting images of incredible quality, resolving objects down to a couple feet in size. The last LRO photos I posted were of the Apollo 11 and 14 landing sites, showing the lunar lander descent stages and some of the footpaths the astronauts left as they scuffed about the powdery surface. This one's even better:

The flag! You can see the flag!

To help you get your bearings, here's what we're looking at. The big white object in the photo above is the bottom half of the Apollo 17 lander in the photo below--basically the legs and gold base. The astronauts blasted off in the top half. The dark traces are footpaths or pairs of wheel tracks left by the Lunar Rover (the dune buggy in the photo below). Other new photos available at the LROC website pinpoint where the astronauts set out scientific instruments and parked the Rover, which is just off the right edge of the photo above. The image width is 102 meters, about the length of a football field plus an end zone. It's fun to compare the LRO pictures to those taken by the Apollo 17 astronauts at the time (again, see LROC).

It's amazing what an elaborate hoax you can create when you've got 40 years to work on it. Of course, I'm part of the "Man really landed on the Moon nudge nudge wink wink" conspiracy, too. My role is to pose as a private citizen and make fun of people who believe in the conspiracy; writing graphic novels is just my cover story. In fact, WHTTWOT was actually written by a team of NASA bureaucrats working in a warehouse in Huntsville, Alabama.

I probably shouldn't have said that.

EDITED TO ADD: I just found this video of the Apollo 17 astronauts blasting off from the Moon, leaving behind the descent stage. This is the very last time anyone saw it before LRO photographed it. The obvious question: Who took the video? It was transmitted to Earth by a camera mounted on the Lunar Rover. So how did it tilt up to follow the spacecraft? I think (maybe Jim or someone else can confirm or correct me) it was controlled from Earth, with the second-and-a-half communications delay taken into account. Either that, or a Teamster working on a soundstage in Area 51 did it.

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Bestest Coolest Picture Ever

From time to time I find and post the "Coolest Picture Ever," usually having something to do with outer space. Got a new one today. This was shot by the HiRISE orbiter that's been circling Mars for months, transmitting images of incredible resolution and quality. Some of my previous "Coolest Picture Ever" candidates were also shot by HiRISE, and that little probe is quickly becoming one of my favorites of all time. (What, doesn't everybody have favorite space probes?)
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What we're looking at are sand dunes on Mars. The fine orange-peely texture is the same kind of wind-driven ripples you'd see in an Earth desert, nothing special. But the dark swirls! Those are caused by dust devils--the little tornado-like vortexes you often see scooting through a field--skipping across the Martian soil. As the dust devils spin, they pick up the fine orange dust, exposing heavier volcanic sand beneath. They do their little dances and die out, leaving these delicate tendril trails in their wake.

[Edited to Add: An anonymous reader who happens to live with me said I should explain what the lighter diagonal band is. That's a steeper slope or cliff face cutting across the terrain, and the parallel gray hashmarks are little landslides that rolled down the side.]

There's more information here and a much larger version here for the truly curious. Images like these constantly renew my amazement at what science can do, and has done in just my lifetime. When I was born, we'd barely managed to loft stuff into orbit, and the best views anyone had of anything off this planet came from Earthbound telescopes. What a world! What worlds!
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New Coolest Pictures Ever

Every few months I find some new photo of space stuff that I immediately dub "The Coolest Picture Ever." These might actually qualify.

NASA recently shot a probe called the Lunar Reconnaissance Orbiter (LRO) to the Moon. LRO is equipped with a high-res camera of unprecedented quality, able to resolve objects down to a couple feet in size. Of course, the first thing you do when you've got eyes that sharp circling the Moon is look for places you've already been. Also of course, this is a very apt week to do so.

The first picture shows the bottom half of the Apollo 11 lunar lander, which was left on the Moon when Armstrong and Aldrin flew away in the top half. Notice its long shadow stretching out to the right.

Impressive enough, but I like this photo of the Apollo 14 site even more. It not only shows the base of the lunar lander but the actual footpath Alan Shepard and Ed Mitchell scuffed in the dust as they set out their equipment! Wow!

I understand that even higher-quality images will be available in coming weeks. None of this will convince the moonbats who think NASA and the U.S. faked the whole thing, of course. After all, who's the source of these pictures? The reality-based rest of us are free to marvel.

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More here.

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Fomalhaut Ho!

It may not look like much, but I've been waiting most of my life to see a picture like this. The Hubble Space Telescope has taken the first direct photo of a planet orbiting another star and there she is, a speck in the small white box toward the right. Named "Fomalhaut b," this little beauty is about 25 light years from Earth--right next door in interstellar terms. The planet is about three times the size of Jupiter and lies far, far away from its star Fomalhaut, 10 times the distance of Saturn from our Sun. It takes 872 years to orbit. That's a looooong year.

Let me explain a few things about the picture. The star Fomalhaut is located at the center, where the white dot is. But, because the star is a billion times brighter than the planet, the telescope blocked out the star's light with a little metal bar so it wouldn't overwhelm dim objects nearby. That bar is the black blotch that runs from the center to upper left. The orange oval is a real feature, a ring of dust that circles Fomalhaut and is partly defined by the planet's orbit. And the inset at lower right superimposes two pictures taken 21 months apart which prove that tiny little dot is actually moving around the star.

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You might be thinking that scientists have discovered new alien worlds around other stars before, and they have. But until now they were all detected indirectly, by measuring how the gravitational pull of an orbiting planet affects the motion of its star, making it wobble as it moves through space. That's interesting and cool, and in recent years has resulted in dozens of new finds. But this . . . well, there's no substitute for seeing something with your own eyes.

If you're interested, click here to go to an official announcement with bigger pictures. Of course this is just the beginning. Astronomers will refine their techniques and improve their instruments. Sometime in my lifetime I would not be surprised to see a clear photo of a little blue and green planet that looks a lot like ours. Wouldn't that be something?

What a great time to be alive.

(Note to my girls: And Bonus! It looks just like the eye of Sauron!)