The image above has been getting a lot of attention on social media lately—I’m getting notes on Twitter and Facebook about it even now, a couple of weeks after it went viral. The caption varies from place to place but generally doesn’t have much info, simply stating a variation of “The Earth as seen from Hubble Space Telescope.”
OK, first, read the title of this article again.
Great. Now, second, this image is in reality CGI created by Mike Kiev (it’s actually part of a very cool animation). I won’t go into details about that aspect of it since Snopes has, as is its usual way, done so capably.
I want to add to what they wrote, though. First, this is nothing like what the Earth would look like from Hubble. For one thing, clouds like the ones depicted tend to be below about 6,000 meters, and the Earth is nearly 13,000 kilometers across. That’s 2,000 times wider! If you saw the Earth as a ball like this, the clouds would barely be discernible from the surface at all.
Also, note the waves in the “ocean.” Those would have to be several kilometers high, which is something I prefer not to think about too realistically. The last time the planet saw waves like that, a huge asteroid or comet had hit off the coast of the Yucatan and the dinosaurs (along with 75 percent of all other species on Earth) were about to have a very bad day.
Also, Hubble orbits the Earth at an altitude of about 570 kilometers. From that height, you can see a swath of Earth roughly 5,000 kilometers across, about the width of the U.S. The edge of the Earth would look curved, but not as severely as shown in the image. I suppose it could have used a fish-eye wide-angle lens, but I don’t think Hubble has anything like that on board.*
Here’s the funny thing though: Hubble used to routinely take images of the Earth. As I wrote on Hubble’s 20th anniversary, some of the cameras used observations of Earth to create a calibration image used to correct the images, a sort of planetary white balance. Hubble orbits at about 8 kilometers per second, so it can’t track the Earth. Instead, the surface streaked by below it, and a time exposure was made to create the calibration data. They looked like this before being processed:
How weird is that? The streaks are actually things on Earth’s surface. They could be rocks, buildings, trees, what-have-you. Maybe you, though that’s a tad unlikely. It’s a big planet.
So that’s what Earth really looks like from Hubble. Perhaps the artist’s image is more fanciful, but to me the reality is just as cool.
*In fact, the widest-angle camera on board Hubble has a field of view roughly equal to the size of a grain of sand held at arm’s length, so yeah. No.