It’s no secret that planet Earth is occasionally greeted by rocks from space that either explode in out atmosphere or impact on the surface. In addition, our planet regularly experiences meteor showers whenever its orbit causes it to pass through clouds of debris in the Solar System. However, it has also been determined that Earth is regularly bombarded by objects that are small enough to go unnoticed – about 1 mm or so in size.
According to a new study by Harvard astronomers Amir Siraj and Prof. Abraham Loeb, it is possible that Earth’s atmosphere is bombarded by larger meteors – 1 mm to 10 cm (0.04 to 4 inches) – that are extremely fast. These meteors, they argue, could be the result of nearby supernovae that cause particles to be accelerated to sub-relativistic or even relativistic speeds – several thousand times the speed of sound to a fraction of the speed of light.
Happen to have clear skies tomorrow morning and live in the western part of North America? Then you may have a chance to spy a unique event, as the waning crescent Moon occults (passes in front of) the planet Mars.
Near the end of 2019, astronomers watching the red giant Betelgeuse noted how much the star had dimmed, continuing to steadily fade for months.
It’s a variable star, and it’s known to get dimmer and brighter, but the big surprise is that it’s still continuing to dim, recently passing magnitude 1.56 and still getting dimmer. This is unprecedented in the decades that astronomers have been watching the star.
Impact craters can be quite complex. Depending on the size of the impactor, and on the size of the planet it strikes, craters form differently. Some form central peaks or uplifted structures, or even pits as seen in this image.
Since the 1960s, there has been a general consensus among astronomers and cosmologists that the majority of the Universe is made up of an invisible, mysterious mass (known as Dark Matter). While scientists still haven’t identified the candidate particle that makes up this mass, indirect tests and simulations have shown that Dark Matter must exist in order for the Universe to be the way it is.
In a fascinating twist, a team of European researchers conducted a simulation that looked at a Universe without Dark Matter. Using an alternative theory known as MOdified Newtonian Dynamics (MOND), the team created a computer simulation in which the galaxies were actually very similar to what we see in the Universe today. These findings could help to resolve one of the most enduring mysteries of modern cosmology.
There are around 61,000 meteorites on Earth, or at least that’s how many have been found. Out of those, about 200 of them are very special: they came from Mars. And those 200 meteorites have been important clues to how Mars formed in the early Solar System.
Thirty years have now passed since the Voyager 1 spacecraft
snapped one of the most iconic and memorable pictures in spaceflight history. Known
as the “Pale Blue Dot,” the heart-rending view shows planet Earth as a single,
bright blue pixel in the vastness of space, as seen from the outer reaches of
the solar system.
Now, NASA and the Jet Propulsion Laboratory have provided a
new and improved version, using state of the art image-processing software and
techniques to reprocess the thirty-year-old image. JPL software engineer and
image processor Kevin Gill, whose images we feature often on Universe Today,
led the effort.
A team of scientists in Canada have found a Fast Radio Burst (FRB) that repeats every 16 days. This is in stark contrast to other FRBs, which are more sporadic. Some of those sporadic FRBs occur in clusters, and repeat irregularly, but FRBs with a regular, repeatable occurrence are rare.