Aimlessly Going Forward

blog by Tomas Sedovic

The past 30 years in Space discovery

It's my 30th birthday today, which I don't care for much, but I've realised that a freaking lot has happened in astronomy and astrophysics during that time. Here are some of my favourite picks:

Our galaxy has a supermassive black hole in its centre

Sagittarius A* was discovered as a radio signal in the 1974, way before my time. However, most of the reports that this is indeed a black hole of about 4 million solar masses started coming around 2002 and onward.

Amazingly, this is apparently quite common -- looks like most spiral and elliptical galaxies have a supermassive black hole in their centre.

I've been fascinated by black holes ever since I learned about them. Indeed, I used to judge the quality of an astrology book by the amount of space it dedicated to the phenomena. When I was younger, it was all basically a hypothesis.

That black holes are now real space objects we can (indirectly) observe, they feature in our calculations and that there's a huge one sitting in our galactic centre is absolutely amazing to me.

The Andromeda galaxy will collide with Milky Way

Confirmed in 2012 based on tracking the motion of Andromeda for ~10 years prior. It will collide and merge with the Milky Way some 4 billion years from now.

This will mean that the supermassive black holes in their centres will merge, too.

WHOA!

(the Earth will be mostly unaffected, but who cares when an that point we'll have either moved away, did something with Sun's increased luminosity or died off)

Oh, also, eventually all galaxies within the Local Group will merge with Milkomeda, too.

Pluto!

A year ago, we've done a first Pluto fly by. The New Horizons craft took a ton of beautiful pictures.

Here's Io (one of Jupiter's moons):

Photo of Io by New Horizons

And Charon:

Photo of Charon by New Horizons

But mainly, LOOK AT PLUTO:

Photo of Pluto by New Horizons

Gorgeous.

Ceres

Speaking of dwarf planets, 2015 has seen another close encounter -- this time by the Dawn probe) that visited Vesta and Ceres).

It showed that the bright spot on Ceres is two bright spots.

Bright spots on Ceres

Also, and I think this really needs emphasising: This space probe used fucking ion engines to move around. You can't get more Sci-Fi than that.

Ion. Engines.

Exoplanets

They exist! And they're not rare!

The first confirmed discovery of a planet outside of our solar system happened in 1992.

We have about 1953 confirmed exoplanets right now. 15 years ago, there were none. Also, we have a freaking telescope looking for them now):

Rogue planets

I know, right? They were theorised in 1998 and the first confirmed discovery happened in 2013. Planets that are just roaming the interstellar space, too cool to be part of a solar system.

https://en.wikipedia.org/wiki/Rogue_planet

Universe Expansion

The universe is expanding -- everyone knows that. But the rate of expansion is actually accelerating. The work for that began by two teams studying Type Ia supernovae (one in 1988 and the other in 1994) -- the results published 1998 confirmed that rate of expansion is speeding up.

The term dark energy was coined in 1998 as well and the Lambda-CDM model seems to fit the current observations quite well.

https://en.wikipedia.org/wiki/Accelerating\_expansion\_of\_the\_universe

https://en.wikipedia.org/wiki/Dark_energy

Gravitational Waves

We fucking found em!

This has been a long time coming and we've finally got a hit. In 2015, we've detected a gravitational wave of two black holes merging. It can't get much better than that.

I honestly don't know what's going to come out of this, but every time we've discovered a new method of looking at the universe, our knowledge exploded. Here's to gravitational-wave astronomy!

https://en.wikipedia.org/wiki/First\_observation\_of\_gravitational_waves

And although it's technically the same discovery:

Black Hole Merger

We have had the first discovery of two black holes merging. Oh my god.

Higgs boson

Another long-hypothesised and recently discovered.

It was discovered by the Large Hadron Collider. The discovery took place on the 4th July 2012, which as far as I'm concerned warrants a world-wide holiday that should take a precedence over celebrating one British colony's declaration of independence.

I love that Peter Higgs, one of the physicists who suggested this particle and after whom the boson was named, was actually present during the announcement.

https://en.wikipedia.org/wiki/Higgs_boson

Some other cool stuff that happened

In a sadder turn of events, no one has walked on another world during my lifetime and the people who've ever done it are dying out.

All in all though, these past 30 years have led to amazing discoveries and I can't wait to see what the next 30's going to look like.

Tomas Sedovic on 24 March, 2016