Roughly 90 percent of the biggest black holes are dormant, meaning that they are not actively devouring matter and therefore not giving off any light or other radiation.

Yet dormant is not dead, so when a star wanders too close, the ensuing feeding frenzy - a tidal disruption event - sets off a spectacular fireworks show. 

Venus has an "electric wind" strong enough to remove the components of water from its upper atmosphere, which may have played a significant role in stripping Earth's twin planet of its oceans, according to new results from ESA's Venus Express mission by NASA-funded researchers.

Chiral molecules, compounds that come in otherwise identical mirror image variations, like a pair of human hands--are crucial to life as we know it. Living things are selective about which "handedness" of a molecule they use or produce. For example, all living things exclusively use the right-handed form of the sugar ribose (the backbone of DNA), and grapes exclusively synthesize the left-handed form of the molecule tartaric acid. While homochirality--the use of only one handedness of any given molecule--is evolutionarily advantageous, it is unknown how life chose the molecular handedness seen across the biosphere.

In the race towards the discovery of another planet in our solar system, the ninth or tenth depending on how seriously you take the 2 percent of astronomers who demoted Pluto, scientists are striving to calculate its potential orbit using the tracks left by the small bodies that move well beyond Neptune.  And the calculations may mean even more than 10 exist.

New calculations confirm that the orbits of the six extreme trans-Neptunian objects that served as a reference to announce the existence of Planet Nine are not as stable as it was thought.

When anti-science activists set out to drive astronomy from the state of Arizona by trumping up an environmental hazard, they were failing to prevent a problem that would creep across many places that don't want space science in their neighborhood - light pollution.

Astronomers have used Hubble to measure the distances to stars in nineteen galaxies more accurately than previously possible. They found that the Universe is currently expanding faster than the rate derived from measurements of the Universe shortly after the Big Bang. If confirmed, this apparent inconsistency may be an important clue to understanding three of the Universe's most elusive components: dark matter, dark energy and neutrinos.

I'll be on David Livingston's the Space Show this Friday, 27th May, to talk about my new "Case for Moon". It's main themes are: first, the Moon as our natural first destination in the solar system. Then, planetary protection and biologically reversible human exploration as core principles for human space exploration. Then, the Moon as a gateway for human exploration of the entire solar system, not just Mars.

One belief is that Jupiter's moon Europa has a deep, hidden ocean of salty liquid water beneath its icy shell. Whether the Jovian moon has the raw materials and chemical energy in the right proportions to support biology is a topic of speculation and  the answer may hinge on whether Europa has environments where chemicals are matched in the right proportions to power biological processes. Life on Earth exploited such niches and still does today.

Using the oldest fossil micrometeorites - space dust - ever found, Monash University-led research has made a surprising discovery about the chemistry of Earth's atmosphere 2.7 billion years ago.

The findings of a new study published today in the journal Nature - led by Dr Andrew Tomkins and a team from the School of Earth, Atmosphere and Environment at Monash, along with scientists from the Australian Synchrotron and Imperial College, London - challenge the accepted view that Earth's ancient atmosphere was oxygen-poor. The findings indicate instead that the ancient Earth's upper atmosphere contained about the same amount of oxygen as today, and that a methane haze layer separated this oxygen-rich upper layer from the oxygen-starved lower atmosphere.

Unlike most asteroids, C/2014 S3 (PANSTARRS) was formed in the inner Solar System at the same time as the Earth itself, but was ejected at a very early stage and has not been baked by billions of years near the Sun.

Instead, it has been preserved in the best freezer there is: the Oort Cloud, a huge region surrounding the Sun like a giant, thick soap bubble. It is estimated that it contains trillions of tiny icy bodies.

C/2014 S3 (PANSTARRS) was originally identified by the Pan-STARRS1 telescope as a weakly active comet a little over twice as far from the Sun as the Earth. Its current long orbital period (around 860 years) suggests that its source is in the Oort Cloud, and it was nudged comparatively recently into an orbit that brings it closer to the Sun.