Category Astronomy/Space

Hubble image of Comet Siding Spring before and after filtering, as captured by Wide Field Camera 3 on NASA’s Hubble Space Telescope. Credit: NASA, ESA, and J.-Y. Li (Planetary Science Institute)

When Comet C/2013 A1 (Siding Spring) passed just 140,000 kilometres from Mars on 19th October 2014, depositing a large amount of debris in the martian atmosphere, space agencies coordinated multiple spacecraft to witness the largest meteor shower in recorded history. It was a rare opportunity, as this kind of planetary event occurs only once every 100,000 years...

This is a three-color optical image of a Milky Way sibling. Credit: Sloan Digital Sky Survey

The most-studied galaxy in the universe – the Milky Way – might not be as “typical” as previously thought, according to a new study. The Milky Way, which is home to Earth and its solar system, is host to several dozen smaller galaxy satellites. These smaller galaxies orbit around the Milky Way and are useful in understanding the Milky Way itself. Early results from the Satellites Around Galactic Analogs (SAGA) Survey indicate that the Milky Way’s satellites are much more tranquil than other systems of comparable luminosity and environment. Many satellites of those “sibling” galaxies are actively pumping out new stars, but the Milky Way’s satellites are mostly inert, the researchers found.

This is...

This artist’s impression shows the binary asteroid 288P, located in the main asteroid belt between the planets Mars and Jupiter. The object is unique as it is a binary asteroid which also behaves like a comet. The comet-like properties are the result of water sublimation, caused by the heat of the Sun. The orbit of the asteroids is marked by a blue ellipse. Credit: ESA/Hubble, L. Calçada

With the help of Hubble, astronomers have observed the intriguing characteristics of an unusual type of object in the asteroid belt between Mars and Jupiter: two asteroids orbiting each other and exhibiting comet-like features, including a bright coma and a long tail. This is the first known binary asteroid also classified as a comet.

In September 2016, just before the asteroid 288P made its closest appro...