Saturn’s beautiful rings form a striking feature, cutting across this image of two of the planet’s most intriguing moons: Titan (diameter, 3,200 miles) and Enceladus (313 miles). The rings have been a source of mystery since their discovery in 1610 by Galileo Galilei, but there is not full agreement on how they formed.
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.
At first glance this NASA/ESA Hubble Space Telescope image seems to show an array of different cosmic objects, but the speckling of stars shown here actually forms a single body — a nearby dwarf galaxy known as Leo A. Its few million stars are so sparsely distributed that some distant background galaxies are visible through it.
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.
In a global exoplanet observation experiment, NASA’s Kepler K2 mission and Earth-based observatories on six continents hope to survey millions of stars toward the centre of our Milky Way galaxy. Using a technique called gravitational microlensing, scientists will hunt for exoplanets that orbit far from their host star and for free-floating exoplanets that wander between the stars.
Brown dwarfs are objects that are too large to be called planets, yet too small to shine by nuclear fusion. Two German researchers have taken a careful look at the distribution of nearby examples of these “failed stars” and to their surprise discovered a significant asymmetry in their spatial arrangement.
Several recent news stories have reported that a mysterious anomaly in the orbit of NASA’s Cassini spacecraft around Saturn could potentially be explained by the gravitational tug of theorised Planet 9, existing far beyond the orbit of Neptune in our solar system. However, NASA cannot find any unexplained deviations in the spacecraft’s orbit.
Exoplanet KELT-4Ab, about one and a half times the size of Jupiter, orbits the main star of a three-star system every three days. The system’s other two stars orbit each other once every 30 years while simultaneously orbiting the main star — and the planet — once every 4,000 years. The triple star system lies about 685 light-years from Earth.
Sprawling across Pluto’s icy landscape is an unusual geological feature that resembles a giant spider. This enhanced colour image, obtained by NASA’s New Horizons spacecraft on 14 July 2015, consists of at least six extensional fractures (arrowed) converging to a point near the centre. Curiously, the spider’s “legs” expose red deposits below Pluto’s surface.
© 2019 Pole Star Publications Limited