Dark matter is an umbrella term for matter that no one has directly detected but must be out there or physics at the very large scale makes even less sense than it makes now. Since it does not reflect, absorb or emit light, it is invisible, so whatever it 'is' is only known to exist via its gravitational effects on matter as we know it.
We may have Jupiter to thank for our unusual solar system. 

Before the inner planets we now call  Mercury, Venus, Earth, and Mars formed, a great inward-and-then-outward journey that Jupiter made early in the solar system's history may have torn apart a number of super-Earths - planets larger than Earth but smaller than Neptune - and caused their giant remnants to fall into the sun billions of years ago.
One of astronomy's big questions is why galaxies forming as recently as 1 billion years after the Big Bang contain so much dust. The leading hypothesis is that supernovae, stars that explode at the end of their lives, contain large amounts of metal-enriched material that, in turn, harbors key ingredients of dust, like silicon, iron and carbon.
In 1670, the greatest astronomers, including Cassini and Hevelius, the father of lunar cartography, documented the appearance of a new star in the skies.

Hevelius described it as nova sub capite Cygni — a new star below the head of the Swan — and now it is officially known it by the name Nova Vulpeculae 1670.  It lies within the boundaries of the modern constellation of Vulpecula (The Fox), just across the border from Cygnus (The Swan) and is also referred to as Nova Vul 1670 and CK Vulpeculae, its designation as a variable star. 
Historical accounts of novae are rare and Nova Vul 1670 is both the oldest recorded nova and the faintest nova when later recovered.

Just like the Pharaoh Cheops, who ruled the ancient Old Kingdom of Egypt, ESA’s CHaracterising ExOPlanet Satellite (CHEOPS) could be someday ruling in the field of exoplanet hunting.
ESA’s Rosetta spacecraft has made the first measurement of molecular nitrogen at a comet,  Comet 67P/Churyumov–Gerasimenko,  providing clues about the temperature environment in which it formed. 
A new map of the Moon's strangest volcano show that its explosive eruption spread debris over an area in the Compton-Belkovich Volcanic Complex much greater than previously thought.

By mapping the radioactive element thorium which spewed out during the eruption, they discovered that, with the help of the Moon's low gravity, debris from the unnamed volcano was able to cover an area the size of Scotland, or around 70,000 km2. The eruption, which happened 3.5 billion years ago, threw rock five times further than the pyroclastic flow of molten rock and hot gases that buried the Roman city of Pompeii, the researchers added.

When we think of cosmology, we often imagine the largest telescopes peering into the deepest space, collecting the feeble light from exploding stars or the first galaxies.

But for some cosmologists – like the Galactic Archaeologists – the focus is the local universe, asking if we can learn about the evolution of our own Milky Way from what we see around us.

In the morning of March 20th Europeans will be treated with the amazing show of a total solar eclipse. The path of totality is unfortunately confined to the northern Atlantic ocean, and will miss Iceland and England, passing only over the Faroer islands - no wonder there's no hotel room available there since last September! Curiously, the totality will end on the north pole, which on March 20th has the sun exactly at the horizon. Hence the conditions for a great shot like the one below are perfect - I only hope somebody will be at the north pole with a camera...

(Image credit: Fred Bruenjes;

Astronomers have discovered thousands of exoplanets in our Milky Way galaxy using the Kepler satellite and many of them have multiple planets orbiting the host star.

By analyzing these planetary systems, researchers from the Australian National University and the Niels Bohr Institute in Copenhagen have calculated the probability for the number of stars in the Milky Way that might have planets in the habitable zone.

The calculations show that billions of the stars in the Milky Way will have one to three planets in the habitable zone, where there is the potential for liquid water and where life could exist. The results are published in the scientific journal, Monthly Notices of the Royal Astronomical Society.