Every now and again something weird and wonderful happens in the sky, and for a few minutes I’m totally perplexed about what it is.

And then there’s something that makes me literally gasp and say "WHAT THE FRAK WAS THAT?"

Yeah. Check out this amazing video:

Holy Haleakala! What was that?

The footage is from a webcam mounted outside the CFHT astronomical observatory in Hawaii (another view of it from a different webcam can be found here; sadly, both webcams are on Mauna Kea, not Haleakala). You see some stars and the horizon, then suddenly an ethereal pale arc pops into view. It rapidly expands into a thin circular shell, then fades away as it fills the view. The whole thing takes a few minutes to expand; you can see the stars moving during the event (some of the pixels on the webcam are very sensitive and make stationary "hot spots" in the field of view).

So what is it? Is it a trans-dimensional portal into the future, some wormhole from the Pegasus galaxy, or two alien spaceships battling it out?

In point of fact, we are seeing something related to space war…

I first saw this video on Starship Asterisk, the discussion forum for the wildly popular Astronomy Picture of the Day website. The conversation there about this event is going pretty well, and I think this whole thing has been nailed down to a reasonable series of events. First, let’s look at a still frame from the video:

(more…)

What does a half million galaxies look like? Something like this:

Whoa. That’s a part of a huge image just released by the Canada-France-Hawaii Telescope Legacy Survey Deep Field #1, a ginormous mosaic of the night sky… and by ginormous, I mean GINORMOUS. It covers a solid square degree of sky — 5 times the area of the full Moon — and tips the scale at a whopping 370 megapixels! It took 5 years and several hundred hours of observing time with the 3.6 meter telescope on top of Mauna Kea to get this massive mosaic.

The image itself may look cool and all, but the true power comes when you give in to the dark side you use the interactive zoom feature. You can surf the entire mammoth 370 million pixel image, zooming in on galaxies galore. And you won’t run out of objects to investigate any time soon: there are an estimated 500,000 galaxies in the image. Like the Hubble image I posted about yesterday, almost everything you see in the image above is a galaxy, not a star.

The images were taken to look for very distant supernovae. It was the investigation of these far-flung stellar explosions that led astronomers to determine the Universal expansion is accelerating, and to postulate the mysterious dark energy that powers this phenomenon. The CFHT is being used to map the same area of the sky over and over again, looking for the tell-tale blobs of light that mark the spots of a distant, dying suns. The more of these we see, the better we can nail down the physical characteristics of the cosmic expansion, and of the dark energy about which we know so little.

Of course, astronomers will squeeze a lot of science from this and other images… but it’s also OK to simply scan and pan through them at home, too, marveling that the Universe is so deep and so deeply beautiful.

For more deep and gorgeous images like this, see Hubble Digs Deep to See Baby Galaxies, The Milky Way Bulges with Cannibalized Corpses, Hubble Pokes at a Galactic Bulge, or just search in the Pretty Pictures category of this blog.