Australasian Science: Australia's authority on science since 1938
Out of this World
News from space and astronomy communities around the world.
When Cosmic Giants Meet Galactic Dwarfs
By David Reneke
What happens when two different-sized galaxies collide?
When two different-sized galaxies smash together, the larger galaxy stops the smaller one from making new stars, according to a study of more than 20,000 merging galaxies. The research also found that when two galaxies of the same size collide, both galaxies produce stars at a much faster rate.
New “Puffy Planet” Found
By David Reneke
A “puffy planet” has been discovered, as well as fresh evidence that asteroids have delivered water to exoplanets.
The Australian discovery of a strange exoplanet orbiting a small cool star 500 light years away is challenging ideas about how planets form. “We have found a small star, with a giant planet the size of Jupiter, orbiting very closely,” said George Zhou of The Australian National University. “It must have formed further out and migrated in, but our theories can’t explain how this happened.”
An Underground Ocean on Jupiter’s Largest Moon
By David Reneke
An underground ocean has been discovered on Jupiter’s largest moon.
NASA’s Hubble Space Telescope has the best evidence yet for an underground saltwater ocean on Ganymede, Jupiter’s largest moon. The subterranean ocean is thought to have more water than all of the water on the Earth’s surface.
“This discovery marks a significant milestone, highlighting what only Hubble can accomplish,” said John Grunsfeld of NASA’s Science Mission Directorate. “In its 25 years in orbit, Hubble has made many scientific discoveries in our own solar system. A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”
Galactic Dinosaurs Aren’t Extinct
By David Reneke
Astronomers have found that compact massive galaxies that roamed the early universe have been hiding in plain sight.
One of the biggest mysteries in galaxy evolution is the fate of the compact massive galaxies that roamed the early universe. Astronomers at Swinburne University of Technology believe they have discovered the answer.
“When our universe was young, there were lots of compact, elliptical-shaped galaxies containing trillions of stars,” Prof Alister Graham said. “Due to the time taken for light to cross the vastness of space, we see these distant galaxies as they were in our young universe. However, in the present-day universe, very few such spheroidal stellar systems have been observed.”
Astronomers Locate Oldest Known Solar System
By David Reneke
At 11.2 billion years of age, Kepler-444 is the oldest star with Earth-like planets ever found.
A Sun-like star with orbiting planets, dating back to the dawn of the galaxy, has been discovered by an international team of astronomers. At 11.2 billion years old it is the oldest star with Earth-sized planets ever found, and proves that such planets have formed throughout the history of the universe.
Dawn Closes in on Ceres
By David Reneke
A spacecraft is about to enter the orbit of Ceres, and construction of the world’s biggest optical and infrared telescope has been approved.
NASA’s Dawn spacecraft has commenced its approach to Ceres, a dwarf planet the size of NSW that has never been visited by a spacecraft. Dawn, launched in 2007, is scheduled to enter Ceres’ orbit on 6 March.
This is history in the making, for two reasons. Dawn’s arrival at Ceres will mark the first time that a spacecraft has ever orbited two solar system targets. Dawn previously explored the large asteroid Vesta in 2011, capturing detailed images and data about that body.
Dwarf Galaxy Could Be an Ejected Black Hole
By David Reneke
Astronomers have observed what could be a massive black hole that has been ejected into space after two galaxies collided.
Dwarf Galaxy Could Be an Ejected Black Hole
Astronomers have observed a mysterious phenomenon that could be a massive black hole that has been ejected into space in connection with two galaxies colliding. This may be due to gravitational waves from the collision.
Hubble Finds Kuiper Belt Targets for New Horizons
By David Reneke
The Hubble has found Kuiper Belt targets for the New Horizons program, and monster galaxies are gaining weight by cannibalising neighbours.
The Hubble Space Telescope has uncovered three Kuiper Belt objects (KBOs) that NASA’s New Horizons spacecraft could potentially visit after it flies by Pluto in July 2015.The New Horizons spacecraft, launched in 2006, is the first mission in NASA’s New Frontiers Program.
The Kuiper Belt is a vast rim of primordial debris encircling our solar system. KBOs belong to a unique class of solar system objects that has never been visited by spacecraft.
Mysterious Signals from Beyond Our Galaxy
By David Reneke
Mysterious signals have been detected from beyond our galaxy, and an exoplanet’s size has been measured to an accuracy of 1%.
A split-second burst of radio waves detected by the Arecibo radio telescope in Puerto Rico provides important new evidence of mysterious pulses that appear to come from deep space. They mark the first time that a so-called “fast radio burst” has been detected in the Northern Hemisphere of the sky.
The Search for Alien Polluters
By David Reneke
Astronomers search for alien air pollution, and Earth-based lasers could zap space junk.
We are on the threshold of “sniffing out” signs of alien life on other worlds. By studying exoplanet atmospheres, we can look for gases like oxygen and methane that only coexist if replenished by life. While these gases come from simple life forms like microbes, would advanced civilisations leave any detectable signs?
Australasian Science July/August 2019
