Check out the Visible Earth collection of satellite images and map projections, created by scientists from NASA and around the world.
Check out the Visible Earth collection of satellite images and map projections, created by scientists from NASA and around the world.
Last night in the wee small hours, if the sky was clear and you lived in one of the right places, you could see the Moon move into the Earth’s shadow and become a deep brick red, illuminated only by light that refracts around the Earth.
NASA has provided a map as well as the image above.
Check out the Space School videos from Science Channel:
How big is our galaxy?
This is Carl Sagan’s video, “Consider again that pale blue dot”:
First came the Hubble Deep Field, a long look into a tiny speck of black sky that revealed almost 3000 previously unknown galaxies:
The image was constructed from a series of observations by the Hubble Space Telescope. It was assembled from 342 separate exposures taken with the Space Telescope’s Wide Field and Planetary Camera 2 over ten consecutive days between December 18 and December 28, 1995.
Then there was the Hubble Deep Field South, taken in the southern hemisphere:
The observations were made over 10 days in September and October 1998. The southern image reavealed about 3000 galaxies and it included a quasar.
And finally the Hubble Ultra Deep Field:
The images were collected from September 24, 2003, through to January 16, 2004. The ultra-deep image looks back about 13 billion years. In August and September 2009, infrared data was collected from a new camera. With the infrared data, astronomers identified some very distant, and very early, galaxies. The image contains about 10,000 galaxies, many of them deeply red-shifted.
This video (hat tip harleyk) helps to explain it all:
This came up recently and I don’t recall ever hearing it before. I’m just a Philistine!
Two asteroids passed near Earth yesterday, closer than the moon.
About 20 percent of the known near-Earth asteroids are considered potentially hazardous because of their size and because their orbits come within 4.6 million miles of the planet. NASA is in the process of building a catalog of near-Earth objects that are at least a kilometer, or .62 miles, in diameter.