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How fast is our universe expanding?
Here's a great New ScienceCast video about the controversial Hubble Constant. It's the key to knowing the age of our universe and much more.
September 26, 2017
Sun photobombed Mars encounter with comet Siding Spring
Comet Siding Spring swept closer to Mars than any known comet in recorded history, creating the largest-ever-known meteor shower. But the sun got in on the act.
September 24, 2017
Biblical signs in the sky on September 23, 2017?
A mirror in the sky to "signs" from the Bible's Book of Revelation? Possibly. But this same sky scene has been seen 4 other times in the past 1,000 years. An astronomer explains.
September 23, 2017
Sun on the sky’s equator
Another great explanation of Friday's equinox - plus beautiful graphics - from astronomer Guy Ottewell.
September 22, 2017
See it! Young moon and Jupiter
Wow! So many beautiful photos of something relatively hard to catch … the young moon returning to the evening sky this week next to the bright planet Jupiter.
September 22, 2017
How to see binocular comet C/2017 O1
This faint comet reaches perihelion, its closest point to the sun, on October 14. It’ll be closest to Earth on October 18, passing distantly at about 67 million miles (108 million km).
September 18, 2017
Another X-flare from the sun
We're near solar minimum, but the sun has been active! Click here for a video of solar flares so far in September, 2017 and for news for the sun's most recent X-flare.
September 11, 2017
Giant sunspots, solar flares, aurora alert!
Sunwatchers are still tracking those 2 large sunspot groups making their way across the Earth-facing side of the sun. Then yesterday there was an X-flare! Watch for possible auroras.
September 7, 2017
See an extra-red moon or sun this week?
If you live in the U.S. or Canada, a peculiarly red moon - or very spectacular sunrise or sunset - might be due to smoke from wildfires. Click in for images from Earth and space.
September 6, 2017
Asteroid Florence found to have 2 moons
3122 Florence passed yesterday, biggest near-Earth object to pass so close in a century. Radar revealed 2 orbiting moons! Plus a chart that'll help you spot the asteroid.
September 2, 2017
