If There’s Subsurface Water Across Mars, Where is it Safe to Land to Avoid Contamination?

If Mars is a potential home for alien life, can we land safely anywhere on the surface without introducing contamination of Earth-born bacteria? A new study has some good news and some bad news. The good news is that Mars is likely completely inhospitable to life. The bad news is that Mars is…likely completely inhospitable to life.

Continue reading “If There’s Subsurface Water Across Mars, Where is it Safe to Land to Avoid Contamination?”

Astronomers find a galaxy that had its dark matter siphoned away

The galaxy NGC 1052-DF4 surprised scientists by having almost no dark matter to complement its stellar population. Recently a team of astronomers has provided an explanation: a nearby galaxy has stripped NGC 1052-DF4 of its dark matter, and is currently in the process of destroying the rest of it too.

Continue reading “Astronomers find a galaxy that had its dark matter siphoned away”

A third of the stars in the Milky Way came from a single merger 10 billion years ago

Ten billion years ago the young Milky Way survived a titanic merger with a neighboring galaxy, eventually consuming the whole thing. Now, remnants of that fossil galaxy still swim in our galaxy’s core – and astronomers have discovered that almost a third of the Milky Way’s current population came from that dismantled rival.

Continue reading “A third of the stars in the Milky Way came from a single merger 10 billion years ago”

Most light pollution isn’t coming from streetlights

Light pollution is the arch nemesis of astronomy, spoiling both the enjoyment of the night sky and the professional study of our universe. For years we’ve assumed that streetlights are the main culprit behind light pollution, but a recent study has shown that streetlights contribute no more than 20% of all the pollution, and if we want to solve this vexing astronomical problem, we have to think harder.

Continue reading “Most light pollution isn’t coming from streetlights”