Universe Today

With over 5,000 exoplanets now identified, astronomers have found that our Solar System isn't the only model of planetary formation. There are super-Earths, sub-Neptunes, hot-Jupiters, and Earth-sized worlds orbiting around red dwarf stars. In a new paper, researchers propose how the search for life could adapt to these bizarre environments, expanding the definition of a habitable world. Life could exist without a surface, or using different kinds of solvents than water.

The early Solar System was filled with both hydrogen and oxygen that can chemically bond into water. But did we create all the water, or was some of it inherited from the earlier times, already present in the protostellar nebula? Astronomers have used the James Webb Space Telescope to study a newly-forming protoplanetary system called L1527 IRS, which will eventually become a star like our Sun. They found evidence that water from interstellar space is preserved when it becomes part of a new star system.

If our Solar System seems stable, it's because our short lifespans make it seem that way. Earth revolves, night follows day, the Moon moves through light and shadow, and the Sun hangs in the sky. But in reality, everything is moving and influencing everything else, and the fine balance we observe can easily be disrupted. Could passing stars have disrupted Earth's orbit and ushered in dramatic climatic changes in our planet's past?

In 1912, astronomer Victor Hess discovered strange, high-energy particles called "cosmic rays." Since then, researchers have hunted for their birthplaces. Today, we know about some of the cosmic ray "launch pads", ranging from the Sun and supernova explosions to black holes and distant active galactic nuclei. What astronomers are now searching are sources of cosmic rays within the Milky Way Galaxy. One such source is a pulsar wind nebula sending high-energy particles out to space.

Shortly after astronomers detected asteroid 2024 YR4 on December 27th, 2024, they realized it posed no threat to Earth. But it still might impact the Moon in 2032. The impact debris could threaten satellites and trigger an extraordinarily stunning meteor shower.