As it orbits Jupiter, the icy surface of Europa heaves and falls with the changing pull of its parent planet’s gravity, creating enough heat to likely support a global ocean beneath the Jovian moon’s solid shell. Experiments by geoscientists suggest that this process, called tidal dissipation, could create far more heat in Europa’s ice than scientists had previously assumed.
NASA’s Cassini spacecraft has been in orbit around Saturn since 2004, studying the giant planet, its rings and its moons. Among the myriad microscopic grains collected by Cassini, a special three dozen stand out from the crowd. Scientists conclude these specks of material came from interstellar space — the space between the stars.
Subtle distortions hidden in a stunning Atacama Large Millimetre/submillimetre Array (ALMA) image of the gravitational lens SDP.81 are telltale signs that a dwarf dark galaxy is lurking in the halo of a much larger galaxy nearly 4 billion light-years away. This discovery could help astronomers address important questions on the nature of dark matter.
There are about two dozen so-called hypervelocity stars known to be escaping our Milky Way galaxy, but PB 3877 is the first wide binary star found to travel at such a high speed. The results of a new study challenge the commonly accepted scenario that hypervelocity stars are accelerated by the supermassive black hole at the galactic centre.
You can never predict what treasure might be hiding in your own basement. A researcher looking for a spectrum of a white dwarf known as van Maanen’s star found a 1917 image on an astronomical glass plate from the Carnegie Observatories’ collection that shows the first-ever evidence of a planetary system beyond our own Sun.
Deep radio imaging by researchers in the University of Cape Town and University of the Western Cape, in South Africa, has revealed that supermassive black holes in a region of the distant universe are all spinning out radio jets in the same direction — most likely a result of primordial mass fluctuations in the early universe.
Astrophysicists at the University of Birmingham have used data from NASA’s Kepler space telescope to look at super-Earths, which are planets outside our solar system with a mass 1-10 times the mass of Earth. In particular, the researchers focused on hot super-Earths whose atmospheres have been stripped away by intense radiation from nearby host stars.
Earth does not always spin on an axis running through its poles. Instead, it wobbles irregularly over time, currently drifting toward the British Isles at 17cm per year. These wobbles don’t affect our daily life, but they must be taken into account to get accurate results from GPS, satellites and observatories on the ground.
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