Nine years ago, the International Astronomical Union (IAU) defined what it takes to be a planet, but left the classification of exoplanets for future consideration. With exoplanet discoveries now numbering close to 5,000, UCLA professor of planetary astronomy Jean-Luc Margot describes a simple “planet test” that can be readily applied to bodies orbiting the Sun and other stars.
Orbiting a mere 3,700 miles above the surface of Mars, Phobos is closer to its planet than any other moon in the solar system. Mars’ gravity is drawing in the 17 × 14 × 11 mile body by about 6.6 feet (2 metres) every hundred years. The long, shallow grooves lining the surface of Phobos are likely early signs of its structural failure as scientists expect it to be pulled apart.
Reviewer Steve Ringwood takes a look through a versatile 25mm eyepiece from Baader Planetarium that has a field cross-hatched by an illuminated reticule that permits measurement through sub-divided etched lines. It can also usefully employed as a guiding eyepiece as it is fitted with a T-2 thread, plus 1.25″ and 2″ nosepiece adapters are available.
Astronomers believe that the Earth-Moon system was created in a giant impact 4.5 billion years ago. Southwest Research Institute scientists combined dynamical, thermal, and chemical models of the Moon’s formation to explain the relative lack of volatile elements like potassium, sodium, and zinc in lunar rocks, when compared to those of Earth.
From possible ice volcanoes to twirling moons, NASA’s New Horizons science team is discussing more than 50 exciting discoveries about Pluto at this week’s 47th Annual Meeting of the American Astronomical Society’s Division for Planetary Sciences. The two cryovolcano candidates are large features measuring tens of miles across and several miles high.
The terrestrial fireworks of recent Bonfire Night(s) celebrations in the UK have masked a rather unusual display of natural illuminations, as we are in the midst of the Taurid meteor showers. However, this year’s display of celestial fireworks not only occurs near a new Moon for dark skies, but the double-peaked shower is currently showing signs of unusually high activity similar to the fireball-rich display of 2005.
NASA’s New Horizons spacecraft, speeding toward deeper space at more than 32,000 miles per hour, has successfully performed a series of targeting manoeuvres that set it on course for a January 2019 encounter with Kuiper Belt object 2014 MU69. This ancient body is more than a billion miles beyond Pluto. The propulsive manoeuvres were the most distant trajectory corrections ever performed by any spacecraft.
NASA’s Swift spacecraft has detected its 1,000th gamma-ray burst (GRB). A GRB is a fleeting blast of high-energy light, often lasting a minute or less, occurring somewhere in the sky every couple of days. GRBs are the most powerful explosions in the universe, typically associated with the collapse of a massive star and the birth of a black hole.
Markarian 820, also known as Mrk 820, LEDA 52404 or IRAS F14379+3142, is a lenticular galaxy in the constellation Boötes, about 300 million light-years from Earth. Galaxies like this one are in the transition zone between ellipticals and spirals and lie right where the fork divides in American astronomer Edwin Hubble’s classification scheme of galaxies from 1926.
A team of astronomers working at the National Centre for Radio Astrophysics have discovered an extremely rare galaxy of gigantic size using the Giant Metrewave Radio Telescope (GMRT). Known as J021659-044920, the galaxy is located about 9 billion light-years away, emits powerful radio waves and has an enormous extent of 4 million light-years.
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