When the most massive stars die, they collapse under their own gravity and leave behind black holes while when stars that are less massive reach their end, they explode in a supernova and leave behind dense, dead remnants of stars.

Those are called neutron stars and heaviest known neutron star is two and a half times the mass of our sun while the lightest known black hole is about five solar masses. What's in that "mass gap" between neutron stars and black holes?

A new paper posits some answers.

How a sunset would appear on other planets is a staple of science-fiction. The sun is as fundamental to grounding our existence as the earth, for most of us. Yet lots of people go months without seeing a sunrise or sunset.

That's extreme, but even more extreme is how it would look on Titan. 

Environmental groups believe that living in cities is better for the environment but if there is one thing that COVID-19 has made clear, it's that living in cities is better for spreading infectious disease also. 

Despite having numerous large cities, the U.S. was on the verge of having measles wiped out, but as the anti-vaccine movement spread on the east and west coasts, they brought a resurgence of it. A group of researchers looked for its origins and found it may help provide answers about coronavirus, which is in the same family as the common cold but was discovered to be novel in the 1960s.

Though we've only detected a few thousand exoplanets, there are likely 6,000,000,000 Earth-like ones out there, and that means millions could be "ocean worlds" capable of supporting life.

Right now, our knowledge of ocean worlds is limited to moons like Enceladus around Saturn and Europa around Jupiter. Plumes of water erupt from Europa and Enceladus, so we can tell that these bodies have subsurface oceans beneath their ice shells, and they have energy that drives the plumes, which are two requirements for life as we know it

When called on to explain why he lives in a gigantic mansion with its resulting environmental cost, Academy Award winner, Nobel laureate, and U.S. Vice-President Al Gore said he bought carbon offsets from a company he owned that sold carbon offsets.

Paying himself to emit greenhouse gases sounded ridiculous but a new analysis shows that buying offsets - paying a company to plant trees - can be just plain risky. 

Forests absorb carbon dioxide from the atmosphere, but if they are managed by a group that doesn't believe in logging or clearing brush. If a forest goes bust in a fire all that stored carbon goes up in smoke again.


Credit: David Meikle, The University of Utah

There have been more celebrity suicides during the COVID-19 pandemic and while tragic, they may help to bring great awareness to the risks of depression and anxiety in other populations at all times. Such as pregnant and postpartum women.