# Space News: Asteroids and comets rock, and more!



## Brian G Turner (Oct 3, 2018)

A lot of space news over the past week or so. 


*1. Asteroid rocks*

The big news has been the successful touchdown of landers by the Japanese Hayabusa 2 probe, with three out of four now successfully on the asteroid Ryugu.

The first images are quite extraordinary: New asteroid rover images released

and a short animated GIF shows Ryugu's rotation:


__ https://twitter.com/i/web/status/1045278816619261953
Now the French-German lander (no.3) is on Ryugu, and has already transmitted images from the landing process: Touchdown! Japan space probe lands new robot on asteroid


*2. Comets rock, too*

A new composite image of Comet 67P/Churyumov-Gerasimenko (67P/C-G), taken by the ESA's Rosetta mission, has been released: Image: Comet landscape







*3. TESS finds first exoplanet*

The Transiting Exoplanet Survey Satellite (TESS) was launched earlier this year - its mission, to find thousands of undiscovered planets around other stars. Although it's still only in its warming-up stages, it's still managed to find its first exoplanet: NASA’s new exoplanet-hunter has spotted its first alien worlds

Expect many more to come. 

TESS succeeds the Kepler telescope, which launched in 2009 and was originally intended to run for 3-5 years. Although it suffered technical failures after that period, it's still managed to continue observations - and has recorded over 2,300 exoplanets. However, Kepler is now almost out of fuel, so scientists are rushing to download what might be its very last set of data: Kepler put into sleep mode as telescope's pointing performance degrades


*4. Space bad for guts*

I've already posted a recent link to health issues that can effect astronauts due to zero gravity - but cosmic radiation continues to be an additional danger. The most recent study into this suggests that human intestines may be especially vulnerable to damage - and tumours: Animal study suggests deep space travel may significantly damage GI function in astronauts


*5. New neighbours found*

We already know there are around 150 dwarf galaxies in orbit around the Milky Way - now another four look about to be added: Four newly discovered Milky Way neighbors

These are tiny galaxies - some with just over 1,000 stars - and very faint, hence why they have been hard to detect - and why others might also be out there.

I also can't help wondering what sort of view anyone in them might get of the Milky Way. 

In the meantime, we still don't actually know how large our galaxy is - but we may be getting closer to an answer: Narrowing down the mass of the Milky Way


*6. Planet 9 from Outer Space*

We may have an even closer neighbour, as a recently discovered icy moonlet in the Oort Cloud shows the same clear influence of an unseen planet on its gravity: A newly discovered *extremely* distant icy world points to Planet 9






What's slightly disappointing is that Phil Plait credits the idea of Planet 9 being only very recent - has everyone really forgotten the Nemesis Hypothesis already?  Whatever it is, it must be very cool and dim not to be spotted yet, which sounds more like what we'd expect from a small brown dwarf...


*7. Stars zoom in on galaxy*

We know there are a number of speeding stars around our galaxy - so-called hypervelocity stars. Data from the GAIA observatory has allowed scientists to identify more, with the surprising discovery that rather than being flung from the Milky Way, most are actually rushing in toward it: Gaia spots stars flying between galaxies








> It is possible that these intergalactic interlopers come from the Large Magellanic Cloud, a relatively small galaxy orbiting the Milky Way, or they may originate from a galaxy even further afield. ... An alternative explanation is that the newly identified sprinting stars could be native to our galaxy's halo, accelerated and pushed inwards through interactions with one of the dwarf galaxies that fell towards the Milky Way during its build-up history.




*BONUS!* Did you know you are walking around with your own mini-biome of bacteria, funghi, and chemicals? If you didn't, recently published research shows just how diverse - and individual - it can be: We are bombarded by thousands of diverse species and chemicals, study finds


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## psikeyhackr (Oct 3, 2018)

Does bounding around the surface of an asteroid qualify as roving?


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## Robert Zwilling (Oct 4, 2018)

Space ions bad for guts, soft tissues, organs. I would rather see the tests performed in space. While it may not matter, the particle beams being used to test gut reactions on Earth could be considered to be artificially concentrated compared to what is actually flying around in space. The stuff in space could be the same, have less effects, or more, but I don't think it is the same stuff. It isn't all coming from the same direction. The article says it is difficult to make effective shielding against all the different kinds of radiation. 

The article says using the current shielding technology, it is difficult to protect astronauts from the adverse effects of heavy ion radiation. Does that mean that the astronauts on the space station are not adequately shielded? Or is it being assumed that space vehicles and other situations won't be as well shielded as the space station is. It appears there is a trade off between capability and the actual weight and structure of the shielding. The effort seems to be directed towards a light weight shielding system that blocks almost everything instead of making something that works. 

I would suspect the problem is maximized when a person is walking around. Seems like the shield would be more massive than the space suit. Everything would be massive from the shielding which throws the idea of instant lite weight construction models out the window. You need artificial gravity but you also need shielding. Cheap housing on the Moon or Mars would be burrowing under the surface with a lite weight carousel wheel inside the burrow. 

I wonder if the zooming stars might be indicative of more things not going in the direction we assume them to be traveling in. Maybe there is a lot more movement going in directions we can't detect because of our physical position.


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## Brian G Turner (Oct 4, 2018)

Robert Zwilling said:


> Does that mean that the astronauts on the space station are not adequately shielded?



I presumed they were experimenting with deep space conditions, as the ISS is still protected by the Van Allen radiation belt.


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## Robert Zwilling (Oct 4, 2018)

Talk about hard to reproduce shielding.


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## Bick (Oct 17, 2018)

Very interesting thread Brian.  I like he hopping 'rovers' a lot.  In answer to psiky, bouncing around does suggest the need for a new noun.  They look like tambourines to me...


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## psikeyhackr (Oct 17, 2018)

Robert Zwilling said:


> Space ions bad for guts, soft tissues, organs.
> 
> The article says using the current shielding technology, it is difficult to protect astronauts from the adverse effects of heavy ion radiation. Does that mean that the astronauts on the space station are not adequately shielded? Or is it being assumed that space vehicles and other situations won't be as well shielded as the space station is. It appears there is a trade off between capability and the actual weight and structure of the shielding. The effort seems to be directed towards a light weight shielding system that blocks almost everything instead of making something that works.



The issue is the Earth's magnetic field.  Charged particles from the Sun get caught in the field and due to the physics of electromagnetism get sent into spiraling paths toward that North and South magnetic poles.  That is what causes the Aurora Borealis and Australis.  But that means anything orbiting below the Van Allen belts is protected to a significant degree from the solar wind.   Long term exposure beyond the van Allen belts would be much more dangerous and require heavier shielding.  That is one of the issues for any trip to Mars.  The Moon trips were relatively short.


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## RJM Corbet (Oct 21, 2018)

I love these pictures: just rocks and hills and stuff -- they seem so familiar and earthlike and yet so distant and alien ...


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## RJM Corbet (Oct 21, 2018)

Robert Zwilling said:


> .... I wonder if the zooming stars might be indicative of more things not going in the direction we assume them to be traveling in. Maybe there is a lot more movement going in directions we can't detect because of our physical position.



Perhaps the gravity of a galaxy attracts lone stars?


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