About half of all stars seem to have “super-Earth” planets on orbits closer to their stars than Mercury is to the Sun, but we don’t.Illustration by Vadim Sadovski / Shutterstock
Is Earth unique? Once a grand philosophical question, it has, over the past two decades, become, with the discovery of thousands of planets around other stars our cosmic cousins a scientific one.
One way to address it is to imagine aliens, using present-day Earth technology, searching our solar system for exoplanets. Which of our eight planets would they find? The answer is Jupiter and only Jupiter. Our exoplanet-searching techniques look for the effect of planets on their host star, either through a cyclical gravitational tug, or by periodically blinking out some of the star’s light. Jupiter would only be detectable (for now) through a decades-long radial velocity survey of the Sun. We could measure Jupiter’s approximate mass and orbit. The question then becomes: How common, among known exoplanet
Astronomers have discovered two new giant radio galaxies (GRGs) using the MeerKAT radio telescope at the South African Radio Astronomy Observatory in Cape Town, South Africa.
Newly discovered giant galaxies dwarf the Milky Way
Our universe may be filled with unseen giants. Astronomers have discovered two giant radio galaxies, which are some of the largest-known objects in the universe. This revelation suggests that the enormous galaxies may be more common than previously believed.
Astronomers found the two galaxies in new radio maps that were created using the MeerKAT radio telescope in South Africa.
Radio galaxies, which can be quite common, are brightest in radio wavelengths of light. Centaurus A is a well-known radio galaxy to astronomers. It’s the fifth brightest galaxy in the sky and is about 12 million light-years from Earth.
Two giant radio galaxies – those that release huge beams, or ‘jets’, of radio light – have been discovered with South Africa’s powerful MeerKAT telescope.