From Russia with Rocks

On 15th February 2013 an explosion happened in the air above Chelyabinsk, Russia blowing out windows and doors for miles around. It was not, as many locals thought, a bomb going off but the shock wave created when a huge asteroid hit the earth’s atmosphere. News carriers around the world quickly picked up on the story, inviting experts to come and talk about the meteorite. Experts like me! I was contacted asking whether or not I’d like to go to Russia to film a documentary on the meteor. I, of course, said yes. After several manic days of trying to get visas and cold weather gear I was off.

It was great to be in the place where the meteor actually struck down.  It’s the first time something like this has happened and it’s been caught on camera. By looking at the footage scientists were quickly able to work out what direction the asteroid came from and how fast it was going. The best estimates put it somewhere around the 40,000mph mark.

Meteoroids are small particles of space rock, ranging from dust grains all the way up to kilometre sized asteroids. Meteoroids hit the Earth’s atmosphere all the time, around 50,000 tonnes of them a year. When this happens they, they become known as meteors. Most are small and burn up in the atmosphere, meaning they’re only dust when they reach the ground. By using stations across the globe designed to listen out for nuclear bombs, astronomers managed to work out how much energy the meteor created when it exploded, putting the size of the meteor at about 10,000 tonnes. Meteors of this size are thought to hit the planet once every 100 years or so. While it’s sad that so many people got hurt, it was really fortunate to have the event caught on so many cameras.

On the hunt

A quick explanation to camera before heading out into the snow fields to look for my rocks!

The day after we arrived we headed out into the countryside to ground zero: the spot directly underneath where the asteroid exploded. The fact that the area is covered in snow was actually a huge help to us meteorite hunters. I had to look for tiny holes in the snow, made by the meteorite as they showered from above. When you found a hole you had to dig around it, clearing a ring. Then I had to sift through the snow in the middle and hopefully find a meteorite. A lot of the holes were from mice or bits of tree but eventually me and the team got lucky and we found one! It was about the size of a jelly bean, covered in a black crust and felt really heavy.

Me and my Meteorite

Me with a 1kg meteorite found by the Urals Federal University.

We took the fragment to Urals Fedral University, where they were looking at the fragments already found. The discovered that the meteor was actually a rather average meteor, with about 7-10% iron, which was why the rock felt so heavy. I even got to look at a piece in a travelling electron microscope.

Despite the devastation that this meteor caused it was actually quite small, probably only 15m across, around the size of a house. The one that killed the dinosaurs was about 10km in size. Luckily those only happen every few million years and we’d probably see it coming. Projects like Pan-STARRS regularly scan the sky and can find nearly all asteroids that would risk wiping out all life on the planet. It hasn’t found any that are on a collision course with Earth, so there’s no need to worry. We’re not going the way of the dinosaurs anytime soon.

Meteor Strike: Fireball from Space is currently available on 4OD. If you haven’t seen it already, you might want to give it a look.

The Harvard Computers

The birth of the photographic plate was one of the most revolutionary moments in the history of astronomy. Before, an astronomer would have to spend long hours in the middle of the night, sitting in the cold at an often precariously placed eyepiece. Taking observations often took many hours and careful notation in less than ideal conditions.

The invention of the photograph had two different ramifications for astronomy. Firstly you could leave the plate there for hours, exposed to all the light of the night sky for as long as you could keep it steady. The human eye refreshes every 10 to 12 times a second, and so we can only see the light that falls on the eye in this time. With a plate you can leave it for 30 seconds, 5 minutes or all night if you can track what you’re looking at across the sky, gathering all the light falling on it in this time. This increase in light collection means that you can observe objects that are much dimmer than what can be seen with the human eye.

Secondly, once you have your photo taken and developed you can then take it away and look at it in the comfort of your office or study, in the middle of the day while sitting by the fire, which was much more cosy.

Williamina Fleming

Williamina Fleming

However there was a problem. The young male astronomers, usually PhD students and the like, didn’t think that sitting inside all day looking at photos was real astronomy. At Harvard College Observatory the men working under director Edward Charles Pickering moaned so much and did such a bad job that in 1881 he fired the lot of them, allegedly claiming that ‘his maid could do a better job’. True to his words, Prof. Pickering hired his maid, Williamina Fleming.

However, it transpired that Mrs Fleming was not just any ordinary maid. She was a highly intelligent and educated woman fallen on hard times after her husband abandoned her just when she was ready to give birth to their son. Initially she did simple tasks; clerical duties, copying and ‘computing’ i.e. maths [1]. However over time she began to take on more scientific and complicated tasks, such as looking at and analysing the spectrum produced by shining a star’s light through a prism.

Pickering quickly realised that not only was hiring women considerably cheaper than their male counterparts, they actually did a much better. For the price of one male astronomer Pickering could hire a dozen women, and they were soon known by the unflattering title of Pickering’s Harem, or the Harvard Computers. Together these women catalogued every single star observed in the sky, carefully measuring their colour, temperature, spectra and many other important properties. This was a feat that many thought impossible but after decades of hard work they completed the task. One of the group’s leaders, Annie Jump Cannon, cataloged and categorized over 350,000 stars in her lifetime, finding more stars in just four years than every male astronomer in history to the point put together [2].

The Harvard Computers

The Harvard Computers taken on 13th May 1913 . Back row, left to right: Margaret Harwood, Mollie O’Reilly, Prof. Pickering, Edith Gill, Annie Jump Cannon, Evelyn Leland, Florence Cushman, Marion Whyte, Grace Brooks. Front row: Arville Walker, Johanna Mackie, Alta Carpenter, Mabel Gill, Ida Woods. For more information look here.

The women were often paid less than the secretaries employed by the university and working in such a career was often seen as an admission of spinsterhood. All these women took this job for the love of astronomy and understanding. Many of these women went on to publish astronomical papers in their own right and many were the first women to be granted into the ranks of institutions such as the Royal Astronomical Society and the American Astronomical Society, and many are remembered on the moon having craters named after them. Henrietta Swan Leavitt, was even considered for a Nobel Prize in Physics for her work on Cephid variables that allowed astronomers to measure the enormous distances of the universe. Unfortunately she died before she could be officially nominated [3].

The work of the Harvard Computers was a huge leap forward not just in terms of astronomy but also for women in science. Though they themselves remain relatively unknown their work is still used by countless astronomers, both professionally and amateur, and will be for years to come.

[1] – Women of Science: Righting the Record by Gabriele Kass-Simon

[2] – Ladies of the Laboratory 2 by Lewis D. Eigen

[3] – Miss Leavitt’s Stars: The Untold Story of the Woman Who Discovered How To Measure The Universe by George Johnson