Seven Dwarfs, err, Planets

Summary: In a brand new press release from NASA, the agency has announced a discovery of seven Earth-sized planets, in the habitable-zone, around a single star. This is the largest star system with such properties and I am excited. The discovery was made by the Spitzer Space Telescope and follow up with ground based observatories.

To be fair, only three of these planets are definitely in the habitable zone, but with the right atmospheric conditions, all seven are likely to have liquid water. This exoplanet system has been called TRAPPIST-1 and the densities show that all planets are likely to be rocky planets like the inner planets of our own solar system. Unlike our sun, this star is an ultra-cool dwarf star that allows all of these planets to be closer to their star than Mercury is to our star. With all of these planets being so close, it is possible that an individual standing on the surface of one planet may be able to look up at the sky and see geological features on the neighboring planet without the aid of binoculars. We can barely do this with our own moon despite how close it is.

If you wanted to visit this system, it is relatively close to us, at only 40 light-years away in the constellation of Aquarius. But until we invent better spacecraft we can only take advantage of the nearness by turning more telescopes to the system. Hubble and Kepler are doing follow-up observations and, when it launches, the James Webb Space Telescope will collect further data.

NASA press release
360 VR of exoplanet surface
Nature

Artist's conception of the system based on known diameters, masses, and orbital distances, NASA JPL, Caltech

One More Shot

Summary: The Cassini spacecraft is on the last phase of its mission. It has begun a series of extremely elliptical orbits around Saturn before it will ultimately plunge into the planet and self-destruct. But while it is still working, there is data to collect. Already we have seen new images of the hexagonal clouds at the North pole of the planet and we are getting new images of the rings. But there is one object in particular that some astronomers have their sights set on.

First noticed in 2013 as a long, bright smudge along Saturn's A-ring, the mysterious object, known as Peggy, is one of the new image goals of the mission. There is no clear image of this smudge yet, and it would be a long time before another mission had a chance to photograph this mystery. The team only has until September to get the image, but thankfully Cassini will be flying close to this A-ring and the mysterious object has now been made into one of the last objectives for the mission.

Saturn can sometimes be used as a model for exoplanet formation in other star systems. The rings act similarly to how we believe dust gathers around a star until planets are formed. It is hoped that by studying Peggy more closely, we will gain more insight into the earliest stages of planet formation. Specifically it is hoped to be a model for how planets migrate. In the few years since Professor Carl Murray discovered this object, astronomers have been able to track it's motion and observe as it has drifted closer and further away from Saturn by a few kilometers.

Even more interesting, as scientists looked back through archival data with recent data from Cassini, they discovered that Peggy might have recently broken into two objects. Recent data shows another, smaller object following directly behind Peggy and orbital dynamics seem to indicate that they would have met in early 2015. Now there is the possibility that a collision of some sort caused both the fracturing of Peggy and also the new orbital radius.

Along with hoping to take better resolved images of Peggy, Cassini scientists also hope to determine the mass of Saturn's rings. Dr. Linda Spiker, the project scientist, points out that the mass can provide key clues about the age of the rings. This in turn would help with models of how the moons were formed. With lots of exciting science coming from the ringed planet this year, this is shaping up to be a great year for astronomy.

BBC News

Juno update

Summary: After 5 years and 1.8 billion miles, the Juno spacecraft has made its first flyby of Jupiter. At only 2,500 miles above the cloud tops, this is the closest any spacecraft has come to the gas giant of our solar system.

One of the things that makes Juno exciting is the panoramic colour camera which allows for stunning images to be sent back in addition to data from its other instruments. 

Juno will make 35 further flybys in order to measure Jupiter's water content, magnetic fields, and to look for the possibility of a solid core. Will all of this new data, it is hoped that scientists will have a better idea of how the planets formed in the early solar system.

BBC News

Conception art no longer

Summary: The Alma telescope has captured a first image of its kind. A picture of planetary formation. The star is HL Tau and here we can see the protoplanetary disk that has formed around the star. It is out of this that the planets are formed. The dark rings in the image are the paths carved out by new planets being formed. Astronomers were surprised by how quickly the process was taking place; HL Tau is only about a million years old. It was not expected to have planets forming yet. This adjustment in the timescale of planetary formation could have an impact on how we date our own solar system, and now that we know it forms faster than expected, we might train our telescopes on other stars around this age and hope for similar results.

BBC News

Two New Discoveries in the Solar System

There's not too much to say about these. The first one is an asteroid that has been discovered to have it's own rings. This is the first asteroid we have found that has its own ring system.

BBC News
Nature


The second one is a new dwarf planet that has been discovered outside of Pluto's orbit. There's two main theories on its formation, but it has still yet to be officially confirmed.

BBC News
Nature

Earth's Eternal Magnetic Field

Summary: Below is a link to an article about Earth's magnetic field and its longevity. It also talks about other aspects of the Earth's innards.



Physics Today

Lava World

Summary: The data from Kepler has revealed another planet that would be brilliant inspiration of any sci-fi novel you are trying to write. This planet, Kepler 78b, is mostly rock and iron but extremely close to its host star. This, paired with the theory that it is tidally locked, means that it is reasonable to assume that that side of the planet is completely molten. With that side of the planet being between 2,000C and 2,800C, it is obviously too hot to support life. It is uncertain what the temperatures on the other side of the planet might be or how far down the molten layer goes. This planet is also an enigma because "according to current theories of planet formation, Kepler 78b could not have formed so close to its star, nor could it have moved there." As a bonus, it is also doomed to be slowly pulled closer and closer into it's star which will proceed to rip it apart.


BBC News
Nature

Seventh System

Summary: Astronomers have discovered a seventh planet are the dwarf star KIC 11442793 which, if confirmend, would be a record for a solar system other than our own. The star is 2,500 light years away and its planets orbit much closer than in our system. All seven planets orbit closer than the Earth does from our sun. This last planet was discovered by citizen scientists on Planet Hunters, a website that lets the public sift through Kepler's data to try to identify new planets.


BBC News

Mars Meteorite

Summary: A small meteorite may hold the secret to how Mars lost is carbon dioxide-rich atmosphere to become the planet it is today.
Key points:
-The Lafayette meteorite shows signs of carbonation which suggests that water was on Mars more recently than previously thought.
-This is the first direct evidence for carbonation on Mars which connects with the Curiosity's discovery of carbonates.
-Understanding how CO2 was removed can help us reduce climate change here on earth.



BBC News

Over 1,000 Exoplanets

Summary: The tally of exoplanets has soared to 1,010 listed in the Extrasolar Planets Encyclopaedia. Out of all these, 12 have the potential to be habitable. This listing, though, is a little less reliable because not all of these planet discoveries have been peer-reviewed. NASA only counts those that have been published in an academic journal and thus their tally is currently at 919. Not to mention there is not a solid definition of what a planet is so some could be artefacts or low-mass stars like other candidates before them.


BBC News

Outer Space Plastics

Summary: Cassini probe has detected propylene on Saturn's moon Titan. NASA says that this is the first definitive detection of this plastic ingredient somewhere other than Earth. Because of this, we also know that many other interesting chemicals have formed. Other than the cool idea of plastic on Titan, I cannot figure out what the application of this knowledge will be.



BBC News

Mapping Exoplanetary Clouds

Summary: If you thought meteorologists on Earth had it hard, check out what these NASA scientists have decided to tackle. They have recently mapped the clouds of the planet Kepler-7b almost 1,000 light years away. By using low-res images from Spitzer and Kepler they were able to compile a map of sorts. It was determined that the clear-reflective signature seen on parts of the images would be clouds. One of the interesting finds is that this planet seems to have a very stable climate with very little change over time.
This marks the beginning of a new era of exoplanetary study. No longer are we simply finding them and adding them to our list with a few details such as size, mass, and distance from their sun. We are now beginning to understand the planet itself.



BBC News

Mars update

Summary: Curiosity has found signs that Mars used to have a large amount of drinkable water in its past. In fact, there were at least two wet stages and sufficient water for microbial life to have formed. Curiosity has also found calcium sulfate veins which are an indicator of water movement along with more coarse pebbles to large to be moved by wind, but just the right size to be moved by a flowing river.

What Curiosity has not found, though, is evidence of methane. Previous measurements from Earth or from satellites had indication that Curiosity would find 10 parts per billion or more of the gas. The existing theory for the methane seen from telescopes was that it was produced by small methane-producing mugs that could potentially live underground. But this theory is loosing its base foundation.  As with all science, more measurements must be drawn before a definite conclusion can be reached.

But what's next for the future of Mars exploration? It could be a robotic snake. The idea is that a little snake companion would accompany its big sister vehicle and provide assistance. Whether this is gathering samples from tight spaces or providing an anchor for the vehicle to pull itself out a position it got stuck in. It has the potential to be a quick solution to any number of little issues.



Live Science (drinkable water)
Science Mag (lack of methane)
BBC News (lack of methane)
Live Science (Snake robot)

Neptune's New Moon

Summary: US astronomer Mark Showalter has used pictures from Hubble to spot a new icy moon of Neptune. It was too tiny for Voyager to have picked up but with Hubble's higher resolution he was able to track the white blur across many years of images. It is Neptune's smallest moon measuring only 20 km (12 miles) across and completing one revolution around Neptune every 23 hours.


BBC News

2 New Earths?

Summary: NASA scientists have found two new planets within the habitable zone of a star. These two planets, Kepler-62e and Kepler-62f, are the most earth-like so far. Though they are too far away to study closer with our current telescope technology, in the future we may be able to determine if these planets do indeed contain flowing water.


BBC News: http://www.bbc.co.uk/news/science-environment-22200476