The end of the world

The end of the world, valentine’s days and DA14

 (Source: European Space Agency)

Doesn’t look like much, does it? A fuzzy image of a small fuzzy dot moving passed other fuzzy things.

But I’m getting ahead of myself.

Filmmakers love to produce movies about the end of the world. Armageddon, Deep Impact, Silent Running, etc. Usually it’s a huge asteroid on collision course or the Sun expanding into a Red Giant and swallowing the earth (in 5billion years, so we don’t have to worry so much about that!)

Whilst the “end” of the last Mayan calendar may have passed, it might seem that we’re not quite out of danger yet.

In fact we never will be. Some might say we should be. Were it not for the devastation of the dinosaurs by a massive impact then mammals may very not have had the chance afforded them and ultimately for humans to eventually evolve.

So what is likely to be the ultimate doom for the Earth?

Well here are some of the major ways current thinking for life on Earth to end.

A Supernovae happens on-average about once every 100,000 years per galaxy. And we are overdue one in the Milkyway!

Betelgeuse is such a star that will go supernova and very soon. It could already have happened and we might just not know it yet.

Within ~26 light years the explosion would sufficient to vaporise our atmosphere. At 640 light years away, we are far enough to Betelgeuse to enjoy the view without dying. Fortunately we are probably several billion years away from a star close enough to go supernova close enough…

Space isn’t empty. It looks cold and dark, but moving out there between stars are vast swathes of dust and gas bulldozing their way through the Milkyway. Left over from the formation of the galaxy and/or debris from novae long ago. One such dust cloud is the Coal Sack nebula. It’s huge, 60-70 light years across. Whilst we are some way away, we sometimes forgot that the Sun is moving around the galaxy at 200km/s. The Heliosphere, the sphere of energy and cosmic particles being thrown by the stellar wind are sufficient to keep normal interstellar dust from smothering the solar-system, but something as large as the Coal Sack would simply bulldozer its way thru the galaxy smothering the planets, blotting out the sun and in effect blotting out all the light and warm our sun grants. It would be a cold, slow death for our planet.

But of course we shouldn’t forget filmmakers favourite Death by Meteor.

Nasa tracks over 19000 man-made objects in orbit around the earth as well as around 10000 Near Earth Objects and further out via radar and the Deep Space Network many more objects and of course it’s remote Spacecraft and missions.

Remember that fuzzy dot on the fuzzy background at the start. Its name is DA14, or more correctly Asteroid 2012-DA14. On February 15^th 2013 it will appear slightly clearer than a fuzzy dot. In fact it is going to pass so close to us that it pass between the Earth and the Moon. In fact closer than geostationary satellites.

Fortunately this time they have its trajectory plotted down to fine detail and we are not in danger. But it does remind us of the precariousness of life on our planet.

Something to remember this Valentine’s Day…

Hot and Cold

 Ok so it’s a little bit cold out.

No I’m not talking about the few flakes of snow currently falling on the UK. I mean out in Space.

Below is a chart of the temperature in Space throughout our Solar System.

Closest in to the Sun, Mercury is one of the hottest and coldest places in the Solar System. It has a dayside temp in excess of 400C, with its night-side can be as low as -200C.

Although the temperature of the space around Venus is about 55C which would allow liquid water (and thus possibly life), it’s thick green-house atmosphere drives it’s surface to around 186C.

We like to think of Earth as a temperate world, and fortunately closer to the bottom range of temperatures that allows liquid water. The hottest recorded temp was 71C(!) in the Lut Desert of Iran and the cold being -89C...of course in Antarctica. This would be colder than Mars and lower than the freezing point of CO₂ (dry ice).

Out beyond Mars and the Asteroid belt, space temp starts to become a challenge for spacecraft. Normally their systems would literally freeze up well before they’d reach Jupiter, so they carry isotropic heaters to ensure they keep on working.

Passed Jupiter and it really starts to get chilly! Oxygen liquefies as we pass Saturn and Nitrogen not long after. After Uranus Oxygen & Nitrogen (Air!) actually freezes.

Pluto and Eris (dwarf planets in the Kuiper belt) are a mind numbing -229C & -231C respectively.

Further out, we really reach the vast coldness of space between stars at -250C.

But only in the dark of the emptiness between Galaxies do we find the coldest parts of the Universe, hovering just above Absolute Zero, around 3K, or -270C.

So when you look out the window at the snow, maybe it’s time to just put another jumper on!

Heroes and Blueberries

“Somewhere, something incredible is waiting to be known” – Carl Sagan

When I was young, in our loft was a long white box with plastic covers on each end. It was a telescope. A telescope that our father had made. The first telescope I looked through. To see the moon closer, to see the planets. To see the stars in their glory. That same telescope was donated to our school, had its own housing and  mini-observatory built (even if it did later fall down and become the place to hold the score-board of the cricket pitch!) That same telescope helped underpin a school Astronomy club, that allowed Wednesday afternoons off once-month to go to London to the meeting of the British Astronomical Association, that allowed me to meet, shake the hand of a Legend and get his autograph (“To David, Patrick Moore”).

Spin back to 1969.

I was born 11days before 2 men stood on another world. I am told that I was placed in front of the black & white tv & stared as Neil Armstrong and Buzz Aldrin walked upon the Moon.

This wasn’t the end or even the peak of the space-race, as science fiction, became reality.

More missions to the moon. Voyager stretching out into the vastness of cold black space to photograph other planets close up for the first time. Soyuz & Apollo. Skylab & Mir, Astronauts and Cosmonauts.

These were the reality of my my first decade bolstered with Sci-Fi. StarTrek. Buck Rogers, BattleStar Galactica and of course…Episode IV: A New Hope. They fired the imagination with new worlds, star-fighters and space-travel, hyperspace & warp-speed.

Others as well that spoke of futures where the destiny of Earth and Humanity were questioned; 2001, Dark Star, Silent Running.

A decade which ended with the great Carl Sagan’s Cosmos series.

I think it’s fair to say that my mind & imagination were forever entangled with the vastness beyond our pale blue dot.

Martian Blueberries.

The Opportunity rover has been on Mars for eight years now. Amongst its more recent and interesting discoveries were geological “blueberries” which indicate water in the past.

If you have any comments or suggestions for a future blog subject please let me know below.

In the Beginning

This is Anna’s fault. Or rather is Caroline’s. Or rather it’s mine.

Anna is a teacher. She teaches stuff to small kids. She’s really good. Caroline is a scientist. She agreed to write Anna a lesson plan on some cool Science stuff. I thought I’d do this too, as I know some really cool stuff about space, the planets, the universe and stuff. And I can explain it to my 7yo nephew and answer his questions.

Writing a lesson plan, with links to videos and stuff would be easy… right. Oh dear.

So instead I thought I’d take a step back and look at all the cool stuff I know (or think I know), put it somewhere I could access easily if I needed to explain things, let others see it too, and of course put here all the things I learn and cool things that I find out about from time to time.

Reminders for myself of cool science stuff that has happened or will be happening through out the year (eg Comet ISON). And I have a sieve of brain and until the lottery comes in no PA to remind me of important stuff!

And If I can try and explain stuff or put in links to places that explain the complex in simple terms, , then maybe I will remember & understand them a bit better as well - Higgs-Boson, Quantum theory, Light speed, gravity & space-time, big bang vs big crunch, Fermi principle, Einstein-Rosenberg bridges (worm-holes to you and me), why E does not =Mc²  etc etc.

Don’t for one minute think this is going to be a guide in order explaining the universe. (I think the BBC & Prof Cox) have that covered if you want that). I’ve read a few book and most of them are pretty good. (for example) and there are some other pretty good resources on the web (e.g. Sixty Symbols)

So let’s start with something simple. Something pretty. And possibly the best link on the web (IMO) – Nasa's Astronomy Picture of the Day 15 years of photos, graphics, videos and other things showing and explaining pretty and very cool things in the universe.

In the Shadow of Saturn 
http://apod.nasa.gov/apod/ap110904.html

 It’s from Nasa and edited by one of Astrophysics great heavy-weights, Robert Nemiroff, with whom I’ve bounced some very interesting emails, about some gravitational lensing I spotted in one their photos.

 So each week I will try and put up something cool that is happening in the Universe or about Space, amazing science and “stuff”.

If you've got any thoughts or ideas on things you'd like me to post about, then feel free to leave comments below (please no conspiracy theories...)