The ten most interesting objects in the universe

Ten things chosen for how much they rearrange your head rather than for how big they are. Six of them you can see for yourself.

1. Saturn

   The first time you see the rings through a telescope you will not believe they are real. They look painted on.

   A ringed gas giant, less dense than water, with a hexagon of winds at its north pole. You can see this one.

2. The Orion Nebula

   A place where stars are being made right now, bright enough to find with your own eyes, and close enough that a small telescope shows the shape of the cloud.

   Glowing star-forming cloud, visible to the naked eye as the fuzzy middle “star” of Orion’s sword. You can see this one.

3. The Andromeda Galaxy (M31)

   The light you see tonight set out long before there were any people like us. It is about 2.5 million light-years away, and it is coming towards us.

   The Milky Way’s larger spiral “big sister”, about the furthest thing most people can see with the naked eye. You can see this one.

4. Sagittarius A*

   It gives out no light of its own, and its mass is known anyway: astronomers have watched stars swing round it for more than thirty years, one of them once every sixteen.

   Supermassive black hole at the Milky Way’s centre, 4.297 million solar masses. You cannot see this one.

5. RX J1856.5-3754

   A dead star squeezed into something the size of a city, so dense that a teaspoon of it would weigh about as much as a mountain.

   One of the nearest known neutron stars, glowing quietly from leftover heat with no radio pulses. You cannot see this one.

6. Europa

   More water than every ocean on Earth put together, kept liquid only because Jupiter squeezes the moon on every orbit — and a spacecraft, Europa Clipper, is on its way to look.

   Icy moon hiding a liquid water ocean under its shell, top target in the search for life. You can see this one.

7. The Crab Nebula

   A court astronomer watched a new star appear and wrote it down, and its wreckage is still there to point a telescope at.

   Expanding wreckage of a supernova recorded in AD 1054, with the Crab Pulsar at its centre. Reachable with a small telescope and some patience.

8. Hoag’s Object

   A galaxy nobody can account for, sitting there being photographed. Every explanation offered for the ring has something wrong with it.

   Near-perfect ring galaxy of unclear origin, a ring of blue stars around a separate yellow core. You cannot see this one.

9. The Pleiades (Seven Sisters)

   With binoculars the handful you see by eye becomes a crowd of dozens, all born together about a hundred million years ago.

   Famous open star cluster of young stars, visible to the naked eye as a small dipper-shaped knot of six or more stars. You can see this one.

10. 1I/ʻOumuamua

    Something from another star system fell through ours, was spotted on its way out, and left. It is never coming back and we will never know more about it than we learned in those few weeks.

    First confirmed interstellar object, small and strangely elongated; as it left, it slowed down less than gravity alone explains. You cannot see this one.

🌙 Plan an evening outsideEvery object, one by one