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The high price-tag of getting stuff off the Earth makes it almost impossible for lots of countries to do science in space. But many of them are about to get their first shot.

At the International Astronautical congress last week, the United Nations Office for Outer Space Affairs announced that they'll be launching their first ever space mission in 2021. They hope to send over a dozen experiments from different countries into low-earth orbit for 14 days. 

Any country that's part of the United Nations will be able to participate, but countries without their own space program will be given priority. They will have to pay a fee to be part of the mission, and the official price hasn't been announced yet, but the UN plans to work with sponsors to cover the majority of mission costs.

Over the next year the official mission goals will be decided, but for now countries can submit experiment proposals for any topic from material science to climate change. The final payloads will be chosen in 2018, leaving three years for the countries to develop their experiments. And while they're working, the UN Office for Outer Space Affairs will offer technical support and advice, since many of these countries won't have had much experience designing experiments for microgravity.

Once they're ready, the experiments will hitch a ride to space aboard Dream Chaser, a reusable spacecraft currently under development by the Sierra Nevada Corporation. Like the old NASA space shuttles, Dream Chaser launches with help from a rocket booster, and lands like an airplane. Because it's only the size of a regional jet, it can land at any spaceport or commercial airport that's big enough, including airports in UN member states, without a fancy space centre.

Earlier this year, the UN announced another opportunity for countries looking to experiment is space. They made an agreement with China that will allow UN member states to send experimental payloads and even astronauts to the proposed Chinese space station, which will hopefully be operational by 2022. The UN hopes that opportunities like the Dream Chaser mission and the space station agreement will open doors for many developing countries and inspire students to consider careers in science and engineering.

So big things are happening on Earth. But meanwhile in space there's some earth-shaking news too - or should I say planet-shaking. We've talked about moon-quakes and Mars-quakes before, but now scientists have found evidence of quake activity on Mercury too. According to a new study published in the journal Nature Geoscience, Mercury might still experience Mercury-quakes, even though we thought its tectonic activity stopped a long time ago.

Around 4.5 billion years ago during Mercury's early days, the planet experienced a ton of tectonic activity as it cooled and shrank. While it was shrinking, parts of its crust were under so much pressure that that they broke apart, were pushed together and eventually the pieces slipped against each other. One piece of the crust was pushed upwards, and a cliff called the fault scarp was created. Billions of years of ago a lot of faults scarps formed, because the planet shrank anywhere between three and fourteen kilometres in diameter.

But that was a long time ago, and we thought that Mercury was no longer active - but apparently, it is. According to a new analysis of photos from the Messenger spacecraft, which orbited Mercury from 2011 to 2015, the planet has small fault scarps less than 50 million years old. 

Although that sounds ancient, these cliffs form really slowly, and if new fault scarps are still forming, even today, that means Mercury is still shrinking and cooling down. As the rocky surface shifts, there are Mercury-quakes, which are estimated to be around a magnitude 5 on the Richter scale. Although scientists haven't sent seismometers to Mercury to measure them yet.

In other words, these quakes wouldn't topple any sturdy houses but furniture might shift, or a photo or two might fall off a wall. Even though we learned that small quakes can happen on the moon during the Apollo missions, this is the first time we've seen current evidence of tectonic activity on a planet besides Earth.

On top of having Mercury-quakes, the planet is also warm enough to have a partially molten core, which is still creating a weak magnetic field. Since Mercury is so small and so old, it's also a mystery why it hasn't finished cooling already, so there's a lot left to discover about the thermal evolution of planets.

But hey, with new countries getting their first shot at space science, we'll hopefully have a lot more people thinking about the answers.

Thanks for watching this episode of SciShow Space, and a very special thank you to our patrons on Patreon for making this show happen! If you want to help us keep bringing the world space news, go to patreon.com/scishow, and don't forget to go to youtube.com/scishowspace and subscribe.

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