NASA has found water on Mars

Today, on the 29th of September 2015, we have found water on Mars. This is the first time the life giving liquid has been confirmed on another body than our own planet. To say this is one of the most amazing discoveries in science is an understatement. Life has existed on our planet for billions of years, only possible by the liquid water which covers two thirds of our planet. If we are to ever discover life out there in the Universe, the day we first found water on a planet other than our own will be remembered as the first step!

But let's calm down. What exactly has NASA found? Well, NASA has been looking at the large slopes on the surface of the red planet and have noticed something interesting. Using the Mars Reconnaissance Orbiter, a satellite orbiting Mars, scientists have been studying these slopes and specifically looking at the chemicals present. What they've found is that in the summer months, long trails of salt appear, cascading down the slopes. The cause of this? Salt water trickling down the slopes, depositing the salt behind, before disappearing. The fact these only appear in the summer and disappear in the winter suggests Mars is warm enough in the Summer so that salt water can exist in liquid form. This is therefore evidence that liquid water does still exist on Mars!

Streaks of salt down the side of slopes on Mars are signs of water flow.

But where does this water come from each summer? Well we're still not quite sure, but it could be that the salt itself absorbs the water from the atmosphere. Whatever the reason, water is some how collecting in large enough quantities to create these metre long streaks down the sides of slopes on Mars.

But think back to your school days. Remember when your teacher told you Mars was beyond the orbit of Earth, beyond the goldilocks zone, where less of the Suns energy reaches the surface of the planet. Here, without a thick atmosphere like Earth, any water on Mars is frozen solid. We know this because we can see frozen water ice caps at the poles of Mars. So, how then has NASA found liquid water? Well, some months ago NASA found deposits of salt on Mars and this is the key to the freezing problem. Salt water, like in the oceans on Earth, has a lowest freezing point than pure water. This means whilst pure water on Mars is frozen solid, salt water will remain as a liquid.

We believe that Mars was once covered by a huge ocean of water, millions of year ago when it was warmer. This is far from the case today, but it now seems that at warm points on the planets surface, small trickles and steams of water exist on the surface.

So, if there is water on Mars, is there life? This is a tricky question. We know complex life doesn't exist on Mars (unless there's a colony of super animals living beneath the surface) (which there isn't), but simple life like bacteria is more possible. Whether they could live with such infrequent amounts of water is unknown. The harsh conditions on the surface, a mixture of radiation and extreme temperature, mean that even with a constant supply of water, life might still be impossible.

But this is a problem for another day, today is all about celebrating the discovery of liquid water on Mars. NASA and other space agencies have spent billions of pounds and dollars sending satellites and rovers to Mars, some designed specifically to find evidence of water or life on the red planet. And today all the hard work, by the thousands of NASA and space workers, has been a success. With several rovers still going and even more set to land on Mars in the future, there is still lot's of work to be done to understand this lone little red planet and find out whatever mysteries it still holds!

Want to find out more? Watch my latest YouTube video:

That's no Moon! Oh, wait...

All the worlds doomsayers have been on high alert for the last week as the asteroid 2004 BL86 passed close to the Earth. Of course, when we say close we mean in space scale, which was 1.2 million kilometres, or around 3 times the separation of the Moon and the Earth. The asteroid unsurprisingly passed safely past, as expected (there are many organisations that focus on predicting the paths of asteroids, to watch out for any dangerous ones).

After the panic period, many people were able to spot the asteroid in the night sky last night, which was relatively bright. Such bright asteroids are a rather rare sight, so its always a treat to be able to spot one. But whilst many of us were trying to spot the asteroid with our eyes or binoculars, the team at NASA's Deep Space Network antennae was taking some incredible radio images of the asteroid. Radio waves are reflected off the asteroid which can be seen by the antennae, allowing scientists to see the asteroid even if it isn't illuminated by visible light form the Sun.

http://www.jpl.nasa.gov/images/asteroid/20150126/2004BL86-640.gif

The radio images have allowed scientists to measure the size of the asteroid and study some of the details of its surface. But it was one unique feature that they didn't expect to see. The asteroid has a moon! Just as the Earth has a large body orbiting around it, our very own Moon, the asteroid 2004 BL86 also has a piece of rock orbiting around it. It's had to think of a body 1/40th the diameter of the Earth having enough gravity to have its own visible moon. You can see a time lapse of the asteroid above, where its moon can be seen as the bright spot moving down from the top of the image.

But whilst it was a surprise to the scientists that this particular asteroid has a moon, it's not overall a surprise, as many moons have been found orbiting around asteroids in our Solar System already. Still, it's not something we get to see very often, let alone around an asteroid that we can see clearly in the sky. 

Dwarf planet Ceres shows off its beauty

The NASA spacecraft Dawn, which launched 8 years ago, is finally approaching its final destination, the dwarf planet Ceres. The hard working little satellite has already spent over a year studying the asteroid Vesta, located in the asteroid belt between Mars and Jupiter, and now is on its way through the asteroid belt to Ceres.

As Dawn has been getting closer to Ceres, it's taken some amazing pictures, one of which can be seen above. This picture was taken around 400,000 kilometres from Ceres, but is getting closer and closer and will eventually take the best images we've ever seen of the mysterious little dwarf planet. But even now we can already start seeing some interesting features on the dwarf planets surface. One of which is the bright spot that can be seen on the planets surface (seen below). We don't know yet what causes this, though it is likely a very reflective area on the surface, reflecting back sun light, but we need a bit more time to find out what it is exactly.

The asteroid belt is the remains of planet formation around our sun, that created the Earth and all the other planets billions of years ago. Leftover material formed the ring of rock, dust and ice that forms the asteroid belt, which in turn likely formed Ceres and Vesta. Whilst Ceres is not a proper planet, instead taking the same dwarf classification as Pluto, it was formed in the same way as planets like Jupiter and the Earth, but failed to sweep up all the remaining material in the belt.

With the NASA New Horizons probe reaching Pluto in the near future, this year seems to be the year of dwarf planets. Hopefully we will be able to get some incredible views of these unexplored worlds and better understand how the solar system formed, all those years ago!

The problem with Pluto

Like most of you, I spent the majority of my life being taught that there are 9 planets in the solar system: Mercury, Venus, Earth, Mars, Jupiter Saturn, Uranus, Neptune, Pluto. We were never really taught much about the planets or how they were defined, so we sat happy in our little bubbles.

It obviously came to a shock in 2006 when scientists decided to re-classify what a planet was. But the logic behind their decision does make some sense. More massive objects have been found in the Solar System along with objects of comparable sizes and shapes. The meeting in 2006 wasn't called to demote Pluto. It was called to decide what the definition of a planet should be. These other objects could have been included and we could realistically today be looking at a Solar System with nearer 15 recognised planets. But the requirement was made such that Pluto and the other smaller bodies were re-classified as Dwarf Planets.

Credit: R. Albrecht (ESA/ESO), NASA. http://apod.nasa.gov/apod/ap990213.html

Whilst the arguments and classification may not have been wholly accepted, it was at least based on science.

But it seems that there has been a revolution happening. When presented with the arguments, a group of people from the general public voted that Pluto should be reinstated at a meeting at Harvard University last week. It seems that many people disagree with the previous decision and want change!

But the meeting raises some interesting points. A large part of the argument to re-instate Pluto seems to come from a cultural and historical viewpoint. Pluto was considered a planet for 76 years, it seems wrong to suddenly change this. But the best thing about science is it's lack of opinion. Science is based on facts, statistics and logic. It was these tools that were used to change the status of Pluto and it's these tools that should be used for everything in science. When it was discovered that the Earth wasn't the centre of the solar system there was a huge uproar from people who believed it went against their religion, but now we look back at this and laugh (hopefully!).

So it may be that some day the definition of a planet is revisited and perhaps changed. But I just hope that this is due to scientific reasoning and not people feeling sorry for a giant piece of rock in space...