Even though the black hole at the center of the Milky Way is a monster, it’s still rather quiet. Called Sagittarius A*, it’s about 4.6 million times more massive than our Sun. Usually, it’s a brooding behemoth. But scientists observing Sgr. A* with the Keck Telescope just watched as its brightness bloomed to over 75 times normal for a few hours.

Despite all we know about the formation and evolution of the Universe, the very early days are still kind of mysterious. With our knowledge of physics we can shed some light on the nature of the earliest stars, even though they’re almost certainly long gone.

For decades, astronomers have been trying to see as far as they can into the deep Universe. By observing the cosmos as it was shortly after the Big Bang, astrophysicists and cosmologists hope to learn all they can about the early formation of the Universe and its subsequent evolution. Thanks to instruments like the Hubble Space Telescope, astronomers have been able to see parts of the Universe that were previously inaccessible.

By creating millions of virtual universes and comparing them to observations of actual galaxies, a University of Arizona-led research team has made discoveries that present a powerful new approach for studying galaxy formation.

Astronomers have discovered evidence for the farthest "cloaked" black hole found to date

Since the “Golden Age of General Relativity” in the 1960s, scientists have held that much of the Universe consists of a mysterious invisible mass known as “Dark Matter“. Since then, scientists have attempted to resolve this mystery with a double-pronged approach. On the one hand, astrophysicists have attempted to find a candidate particle that could account for this mass.

There are about 22,000 large objects orbiting the Earth, including working and broken satellites and bits of old rocket from past space expeditions. If you include all the equipment dropped by astronauts while floating in space and the debris from colliding satellites down to around 1 centimeter in size, there are about one million bits of space junk in Earth’s orbit.

Since the first use of electric lamps in the 19th century, society hasn’t looked back. Homes and streets are lit at all hours so that people can go about their business when they’d once have been asleep. Besides the obvious benefits to societies and the economy, there’s growing awareness of the negative impact of artificial light.

When astronomers discover a new exoplanet, one of the first considerations is if the planet is in the habitable zone, or outside of it. That label largely depends on whether or not the temperature of the planet allows liquid water. But of course it’s not that simple. A new study suggests that frozen, icy worlds with completely frozen oceans could actually have livable land areas that remain habitable.

In the hunt for life on other worlds, astronomers scour over planets that are light-years away. They need ways to identify life from afar — but what counts as good evidence?

A piping hot planet discovered by NASA’s Transiting Exoplanet Survey Satellite (TESS) has pointed the way to additional worlds orbiting the same star, one of which is located in the star’s habitable zone. If made of rock, this planet may be around twice Earth’s size.

Even though we can see the Moon shining brightly in the night sky – and sometimes in daylight – it’s hard to put into perspective just how large, and just how distant, our nearest neighbor actually is.