GN-z11

18 galactic-years

about 225-250 million years

Same time last galactic year – the Jurassic Period It lasted approximately 56 million years, starting at the end of the Triassic Period, around 201.3 million years ago, and ending at the beginning of the Cretaceous Period, about 145.5 million years ago.

220, 230 million years

It shows a newly discovered dwarf galaxy – called Bedin 1 – hidden behind the globular cluster’s stars. Astronomers found this little galaxy while using the Hubble Space Telescope to photograph the globular star cluster, which is located 13,000 light-years away in the halo of our home galaxy, the Milky Way.

Even though, at any given instant, there’s only around 10-22 kilograms of dark matter inside you, much larger amounts are constantly passing through you. Every second, you’ll experience about 2.5 × 10-16 kilograms of dark matter passing through your body.

When antimatter and regular matter touch together, they destroy each other and release lots of energy in the form of radiation (usually gamma rays). If it’s a small amount, it’s totally safe.

This positron signature could have a variety of causes, but a prime candidate is dark matter, the intangible stuff thought to make up about 98 percent of all matter in the universe. When two dark matter particles collide they can sometimes destroy each other and release a burst of energy that includes positrons.

Due to its explosive nature (it annihilates when in contact with normal matter) and energy-intensive production, the cost of making antimatter is astronomical. CERN produces about 1×10^15 antiprotons every year, but that only amounts to 1.67 nanograms.

But in superdense pulsars they might accumulate enough to do damage. “Dark matter can’t collect as densely or as quickly at the center of regular stars,” Bramante says, “but in pulsars the dark matter would collect into about a two-meter ball. Then that ball collapses into a black hole and it sucks up the pulsar.”