Tag: pluto

Mars, Pluto and protecting Earth from asteroids

Hey everyone, just a quick post for today to summarise some stuff I’ve read that I thought was pretty cool.

Apparently the cost of travelling to the Moon can be reduced by a factor of around 10; down to $10 billion US from $100 billion US. Utilising water and hydrogen on the lunar surface as fuel, this can also significantly reduce the cost of travelling elsewhere in the Solar System. This of course flies in the face of Dr. Robert Zubrin’s claim that we don’t need to go back to the Moon to get to Mars. The study says that in 10 to 12 years, a four-person industrial base on the Moon could be built at a cost of $40 billion US. Of course, as the study admits, the fuel resources are not guaranteed, and some kind of exploration would have to be undertaken to prove their existence in quantities large enough to be worth extracting. Check out the summary article here or the report here. The report is a long read and I’m still working my way through it; I’ll put up my own summary when I’ve finished.

This article by Tanya Harrison explains how some of the cool surface features at Mars’ south pole formed, and tell you how YOU can help map Mars! Click here to check out the Zooniverse project that puts you in the scientists’ chair to pick surface features on imagery taken by the Mars Reconnaissance Orbiter.

So it turns out Pluto is red, and the reason is ‘tholins’. What are tholins? They’re basically complex organic molecules. Find out more about these and the implications here.

Finally, the B612 Foundation is worth looking into if you haven’t already heard of it. Simply put, they aim to enhance our capability to protect Earth from future asteroid impacts which can be potentially catastrophic for our civilisation through science, technology, advocacy and education.

Until next time.

Making history with Pluto

Last night I watched the live stream from NASA TV of the New Horizons team and onlookers as a space probe reached Pluto for the first ever time. There were no images at the time, as the radio signals take over 5 hours to reach Earth from Pluto. Also, as I found out last night, to reduce the risk of equipment failure New Horizons can only send data back to Earth when it is not doing science and taking photos. The antenna itself to return data to Earth does not move, and so it must be pointed at Earth by turning the probe itself, and therefore the science instruments away from Pluto. Despite this, the atmosphere was incredible, with many crying for joy.

The first images have come in, and courtesy of the xkcd web-comic we have our first geological interpretation of Pluto.

In all seriousness, I’d like to turn your attention to the so-called heart of Pluto. This incredibly large patch of Pluto’s surface appears almost completely devoid of surface features. Scientists are already speculating that this is due to ongoing geological processes at work under the surface. For this to be the case, Pluto must remain quite geologically active today – rather unusual for such a small planetary body! If the surface had not been recently active, this area should be riddled with craters from asteroid and comet impacts like the rest of the surface.

One possible explanation that comes to mind is in the form of the Lunar mare, the large, dark basaltic planes on the Moon formed by volcanic eruptions. These eruptions are thought to be the result of asteroid impacts that had enough force to induce widespread volcanism on the surface. These areas are relatively smooth as the young volcanism covers any trace of impacts.

The heart has roughly the right shape to have been caused by several such events, but it is unusual that the region is a lighter colour than the rest of the dwarf planet. This could possibly be the result of a more felsic magmatism? Or I could be way off. Comment your thoughts below!

Until next time.

Pluto, measuring gravity with probe swarms and more!

A lot of exciting space science news coming in this weekend! Lets start with this project brief from Johns Hopkins University.

The proposal is to use a series of orbiting probes and a mothership to measure the gravity field of an asteroid or comet, and use this information to model the internal structure. Modelling the interior of small planetary bodies is something that we haven’t achieved yet as a species, simply because most of our exploration tools focus on large scale and surface features. We haven’t been able to put a drill hole into the centre of an asteroid yet!

Scientists are turning to remote sensing techniques like gravity, ground penetrating radar and radio tomography (think penetrating an asteroid with lightwaves of different frequencies and measuring the signal returning signal bouncing off different internal structures) to cheaply gather data on an asteroid’s interior.

In the above proposal the mothership will precisely monitor the position of the orbiters as they rotate the asteroid. Even a small change in orbit will reveal changes in density which can be caused by heavier or lighter material and empty spaces within. The combined data will be used to build a picture of the asteroid’s interior. This technique is already shown to be feasible through a series of simulations.

The benefits of such a project include the mothership being able to perform other experiments simultaneously, even leaving room to send a lander to the surface.

My only concern is in accurately tracking the position of the orbiters with respect to the asteroids surface. On Earth we need 4 GPS satellites to provide accurate location coordinates.

In other news, an incredible new photo reveals signs of geological features on Pluto, making a geophysicist like myself giddy with excitement. Even with a resolution of 27 kilometres, breathtaking new features can already be made out.

I think my reaction can be neatly summarised by this photo of science team members.

While it is unlikely that Pluto is still geologically active due to its small size, it seems apparent that it underwent a series of events leaving clues on its surface to its past.

As New Horizons principal investigator Alan Stern said, “After nine and a half years in flight, Pluto is well worth the wait.”

Different materials reflect various wavelengths of light in different proportions. As a result, each material has its own characteristic spectral signature.

Even with the most advanced telescopes, the light from distant planets beyond our solar system constitute a single pixel. This makes it hard to look for life, as the light signature from a planet gives us only the average of the near side of the planet.

Researchers from the University of Washington and the Virtual Planetary Laboratory published a paper in May in Astrobiology. They have found that if an organism with nonphotosynthetic pigments (which use light for things other than energy) cover enough of a planet’s surface, their influence on the spectral signature could be strong enough to be detected by a new generation of telescopes currently in development.

This possibility has been overlooked in previous searches for life, and while there are some difficulties with this method, it certainly broadens our ability to detect life at great distances.

A link to the original paper can be found here.

Until next time.

New Horizons – Journey to Pluto

After 9 years, only 5 days remain until New Horizons performs its flyby of Pluto!

Time to brush up on our (my) knowledge of this ex-planet.

“Did you know that until very recently, the best images we had of Pluto were just a few pixels in size? That’s right: those pictures you have in your head of what Pluto looks like are mere artists’ impressions.”

No!

During New Horizons’ close encounter we will see imagery revealing details as small as 50 metres across. For a sneak peak at what’s in store, check out this photo New Horizons took as it passed Jupiter.

Jupiter and Io taken by New Horizons in 2007 - image sourced from abc.net.au.
Jupiter and Io taken by New Horizons in 2007 – image sourced from commons.wikimedia.org.

New Horizons will pass as close as 12,500 km from Pluto, taking high resolution imagery as it floats by. It will take as long as 16 months to return 1 day worth of photos to Earth due to the probes’ low bandwidth!

I’m excited to see what insight we can get into the geology of Pluto with these images. Given how little we know about it, the little data we get from the imagery and New Horizons’ other equipment will surely yield some incredible discoveries!

Unfortunately, after Pluto, New Horizons is destined for a lonely journey through the Kuiper Belt, an icy ring of debris beyond Neptune. While there are millions of objects in this belt, they are few and far between, leaving New Horizons very unlikely to come into contact with one.

From there it will be on to the Oort cloud, and finally,  interstellar space.

For a more detailed summary of Pluto, check out this article by ABC News.

Until next time.