Dean W. Armstrong

A number of visible passes for Chicago this week: http://www.heavens-above.com/PassSummary.aspx?satid=25544&lat=41.781312&lng=-87.60...

with the Pleiades and a rising Moon.

The eclipse season continues, as the Moon's nodes--the intersection line of the Moon's orbital plane and the Earth's orbital pla...

In addition to causing breast cancer, light pollution has now been shown to affect the atmospheric chemistry at night in urban regions, inc...

A rare occultation of a star by the Kuiper Belt Object known as Eris was recorded in several stations in Chile and at first glance the data ...

Oh man, this is great . The radar images from last week indicated the comet was dog-boned shaped but the close-ups from the former Deep Imp...

The bright "star" next to the nearly Full Moon tonight was Jupiter, in case you were wondering.

Hi. I've spent much of my life outside at night looking up. I've seen some amazing things. I've never seen a UFO. I've s...

Phil Plait points out pits on the Moon ! Click to enlarge. Images via NASA/GSFC/Arizona State University/LROC

The SDSS and e-science archiving at the University of Chicago Library Barbara Kern, University of Chicago Dean Armstrong, University of Chic...

http://www.nytimes.com/2010/08/27/science/space/27planet.html?hp

http://www.skyandtelescope.com/observing/home/101264994.html My first thought once it was confirmed was "What is the real rate of visib...

Hey, this is pretty cool; I'm always a fan of planetary conjunctions. Saturn was visible in a few of the images of Lutetia taken by Ros...

Another successful asteroid fly-by! http://www.planetary.org/blog/article/00002577/

Inspired by a query regarding the false meme going around about Mars, I took a look at some images I took of Mars during it's big opposi...

Link and run: http://arstechnica.com/science/news/2010/06/breaking-news-jupiter-hit-by-yet-another-impactor.ars

Jupiter's South Equatorial Belt, normally a brown-red, has gone as pale as the cream white zones surrounding it. Check out the report w...

This is great; I've been holding off on sharing this because I felt like it was too special to share widely. But here's the deal--t...

Color me surprised: I did not believe, when this object was first reported, and further debate on the Minor Planet Mailing List, that this w...

The bright orange "star" next to the Full Moon tonight and Friday is the planet Mars, which happens to be closest to Earth tonight...