Space News & Blog Articles

Nature often defies our simple explanations. Take comets and asteroids, for example. Comets are icy and have tails; asteroids are rocky and don’t have tails. But it might not be quite so simple, according to new research.

The Earth’s place in space is a fairly familiar one with it orbiting an average star. The star – our Sun – orbits the centre of our Galaxy the Milky Way. From here onwards, the story is less well known. The Milky Way is part of a large structure called the Laniakea Supercluster which is 250 million light years across! That really is a whacking great area of space and it contains at least 100,000 galaxies. There are larger superclusters though like the newly discovered Einasto Supercluster which measures an incredible 360 million light years across and is home to 26 quadrillion stars!

There are plenty of craters on Mars, especially when compared to Earth. That is primarily thanks to the lack of weathering forces and strong plate tectonics that disrupt the formations of such impacts on our home planet. However, not all impact craters on Mars are directly caused by asteroid impacts. Many of them are caused by the ejecta from an asteroid impact falling back to the planet. One recent study showed how impactful this can be – it concludes that a single large impact crater on Mars created over two billion other smaller craters up to almost 2000 km away.

We are all too familiar of the Moon’s effect on our planet. It’s relentless tug causes our tides but even Mars, which is always at least 55 million kilometres away, can have a subtle effect too. A study has revealed a 2.4 million year cycle in the geological records that show the gentle warming and cooling of our oceans. The records match the interactions between the orbits of Earth and Mars over the longest timescales. These are known as the ‘astronomical grand cycles’ but to date, not much evidence has been found. 

We, and all other complex life, require stability to evolve. Planetary conditions needed to be benign and long-lived for creatures like us and our multicellular brethren to appear and to persist. On Earth, chemical cycling provides much of the needed stability.

Universe Today has examined the importance of studying impact craters, planetary surfaces, exoplanets, astrobiology, solar physics, comets, and planetary atmospheres, and how these intriguing scientific disciplines can help scientists and the public better understand how we are pursuing life beyond Earth. Here, we will look inward and examine the role that planetary geophysics plays in helping scientists gain greater insight into our solar system and beyond, including the benefits and challenges, finding life beyond Earth, and how upcoming students can pursue studying planetary geophysics. So, what is planetary geophysics and why is it so important to study it?