Space

Would you want to live on a "snowball planet", covered with ice sheets and glaciers all the way to the equator? Mars only looks warm because the photos are digitally adjusted to match brighter lighting on Earth, and because it lost most of its water long ago.

It's so cold at the equator (warmest places on Mars) that carbon dioxide could freeze to dry ice at night. On Earth this only happens in the coldest spots in the interior of Antarctica in the middle of winter.

This is just one of many reasons why Mars is less than ideal as a place to live. This is an update of my Ten Reasons not to Live on Mars, Great Place to Explore.

Results using data from the Gaia-ESO project has provided some evidence backing up theoretical divisions in the chemical composition of the stars that make up the Milky Way's disc – the vast collection of giant gas clouds and billions of stars that give our Galaxy its 'flying saucer' shape -  and suggesting that stars in the inner regions of the Galactic disc were the first to form.


A young star named HD 142527 in the constellation Lupus (the Wolf) has revealed that cosmic dust, which is component material of planets, is circling around the star in a form of asymmetric ring. 

By measuring the density of dust in the densest part of the ring, astronomers imaging it with  the Atacama Large Millimeter/submillimeter Array (ALMA) found that it is highly possible that planets are now being formed in that region.

In Trouble with Terraforming Mars, I looked at many things that could go wrong with such a project. But setting aside those issues, Mars terraforming takes us far into the realm of magical thinking - where if you can imagine something vividly, you can make it happen. 

In this imagined future, with the ability to use giant space mirrors to warm up Mars, it is also easy to solve the energy crisis on Earth - just beam all the energy we need back to Earth from space solar power stations. With the fine control we need over planetary atmospheres, it is a trivial matter to adjust levels of CO2 from 0.04% back to 0.03% and stop global warming instantly.

We haven't found life on Mars yet. That's not too surprising, though disappointing. You can see its surface geology from orbit, plain to view, but any life is likely to be hidden inside rocks, under the soil or beneath the ice.

Pristine deposits of ancient life are likely to be buried meters below the surface, or recently exposed. Any organics left on the surface for long periods of time get destroyed by cosmic radiation and some other process, probably chemical.

By observing a high-speed component of the massive galaxy cluster MACS J0717.5+3745, an extraordinarily dynamic cluster with a total mass greater than 1015 (a million billion) times the mass of the sun or more than 1,000 times the mass of our own galaxy, researchers have detected for the first time in an individual object the kinetic Sunyaev-Zel'dovich effect, a change in the cosmic microwave background caused by its interaction with massive moving objects.  \


The surface of Venus is totally hostile to Earth life, a dim, hot furnace, with temperatures well over 400°C. But conditions are different at the Venus cloud tops. Temperatures are ideal, with plenty of light. The atmosphere is out of equilibrium, with H2S and SO2 present together, which life could use as a source of energy. Our orbiters have detected Carbonyl Sulphide - a clear sign of life here on Earth (though it could be created inorganically on Venus); and particles which are non spherical like microbes and the right size for them.

The near-infrared vision of NASA's Hubble Space Telescope has given us a new view deep inside the Tarantula Nebula - and its more than 800,000 stars and protostars within.


Messier 83, the Southern Pinwheel Galaxy, is one of the largest and closest barred spiral galaxies to us.  At 15 million light-years away, it is one of the most conspicuous galaxies of its type in our skies.  It's in the constellation of Hydra (The Sea Serpent) and is a prominent member of a group of galaxies known as the Centaurus A/M83 Group, which also counts dusty Centaurus A  and irregular NGC 5253 as members. 

Spiral galaxies come in a range of types depending on their appearance and structure -- for example, how tightly wound their arms are, and the characteristics of the central bulge. Messier 83 has a "bar" of stars slicing through its center, leading to its classification as a barred spiral. The Milky Way also belongs to this category.


The most scientifically interesting objects are not the bright blueish white ones in the center of the image, but the small reddish looking ones off to the sides.  Here's how and why.