EXOPLANET SERIES – TRAPPIST-1

On Wednesday NASA made headlines by announcing that researchers had detected seven exoplanets orbiting a dim dwarf star.  These exoplanets are determined, based on measurements, to be approximately Earth-sized solid planets and three happen to fall in the “Goldilocks Zone” where water could exist in liquid form; not too hot, not too cold.  Lots of people started speculating that in a few years we’ll find out if one of those planets harbors life.  However that is just plain crazy-talk.  The importance of this discover is that complex exoplanet systems do exist; the Solar System is not an exception, and that life is also not an exception.

The TRAPPIST-1 system

The TRAPPIST-1 system contains a total of seven planets, all around the size of Earth. Three of them — TRAPPIST-1e, f and g — dwell in their star’s so-called “habitable zone.” [NASA/JPL]

0.60m Ritchey-Chrétien Reflector [TRAnsiting Planets and PlanetesImals Small Telescope–South / ESO]

0.60m Ritchey-Chrétien Reflector [TRAnsiting Planets and PlanetesImals Small Telescope–South / ESO]

The TRAnsiting Planets and PlanetesImals Small Telescope–South made the discovery back in May 2016 of three exoplanets around the small star.  But it was with the help of larger telescopes and the space-based Spitzer telescope that the count increased to seven and their orbits could be confirmed.  What I find interesting is the initial discover was done by a relatively “small” 0.60m telescope.  OK not your typical backyard astronomy gear, but scale that down by 1/3 and you have equivalent optics for about $3000.  Add a mount and CCD and for $10,000 you could probably have your very own exoplanet hunter!

Back to the crazy-talk of finding life in this exoplanet system… Anyone who has studied the history and formation of the Solar System knows that there have been a series of unlikely events that have led to where we are today.  Starting with the Sun, probably a 3rd generation star, where heavy elements like Calcium and Iron necessary for life as we know it were produced by previous stars and supernovas that used to exist in this spot of the galaxy we now occupy.  All elements beyond Hydrogen are produced by stars, either through fusion or when they dramatically explode as supernovas.  The atoms making up the air, the trees, the oceans, ourselves were not created in our Solar System during its formation.  The Sun is currently only generating Helium and Lithium out of Hydrogen through the wonders of fusion.  All the heavier atoms within us were created by previous stars that no longer exist.  Hence for solid Earth-like exoplanets to exists there needs to have been one to two previous generation of stars in the region.

An alien race observing our Solar System would surely first spot Jupiter.  One could almost say that it characterizes our home in this part of the galaxy.  With its strong gravity this gas giant plays the vital role of neighborhood vacuum cleaner.  It is either mopping up or launching away asteroids and comets that would otherwise impact Earth, bringing relative calm to the inner Solar System.  If Earth was constantly bombarded by solar objects, there is no way that life could suitably evolve from slimy unicellular organisms.  It took 3 billion years for multi-cellular organisms to show up once life appeared on Earth.  If cataclysmic comet and asteroid impacts are a frequent occurrences, then there is little chance that complex organisms would come to be.

Looking at another element, TRAPPIST-1 is described as an ultra-cool dwarf star just shy of 40 light years from Earth in the constellation Aquarius.  If we forget that it’s a fraction of our Sun’s size and brightness (hence heat generation), it is relatively young at 1 billion years old.  So while there may be three planets that could be habitable, life may not have even begun yet.  Our own Sun is 4.3 billion years old, and the animals we see around us have only been around for the last 14-16 million years.  So what could be in a 1 billion year old planetary system? Assuming all the ingredients are there for life to exist, you probably only have bacterial soup.

Now, my article was getting long, and I wanted to cover many more subjects, too many for a single article.  Hence I’ve decided to break them out into the EXOPLANET SERIES and will publish them over time.

 

2017 Event : Total Solar Eclipse for North America

Every given year there are between two and five solar eclipses, this upcoming one for August 21st will be special.  The last total solar eclipse for North America goes back to 2008.  As Earth is largely covered by water, many of the eclipses are over the ocean where the number of viewers are limited.  But this one will pass over millions of people, all with access to equipment and social media to share their experience.  Hence this one has lots of people planning and getting ready.  The eclipse is most impressive when you’re located in the path of totality; where the Moon completely blocks out the Sun.  Hence if you are able to travel to such a location along its path, it will be worth it.  I also suggest finding a local astronomy group or association as they will most-likely have telescopes and other special observing gear out for everyone to use.

August 2017 Total Solar Eclipse.

The total solar eclipse will only be viewed in the narrow path crossing the middle of the USA. North and south of that will get a partial eclipse. The green vertical lines indicate the time of maximum eclipse. Courtesy Michael Zeiler, GreatAmericanEclipse.com.

Observing the solar eclipse requires protective eye-wear and solar filters for any observing or photographic equipment.  For my telescope it’s a film solar filter, now branded SolarLite by Thousand Oaks Optical.  These can be purchased already mounted in an aluminium cell or in sheets for your own custom application.

Thousand Oaks Optical R-G Solar Filter

Thousand Oaks Optical R-G Solar Filter

The American Astronomical Society has created a web site just for the event with plenty of information on safe observation and suppliers of necessary optical filters.

Stay tuned…

JunoCam – Revealing Jupiter from New Angles

JunoCam onboard the Juno spacecraft is providing us with some great pictures of the Jupiter cloud top, but from the rarely seen polar angle.  Pretty much all spacecrafts that have visited Jupiter did so with a fly by along the equatorial plane, which is also the same plane we observe Jupiter here on Earth.  However with the Juno spacecraft, we now have a chance to enter into a polar orbit and take pictures of the polar regions.

Part of the reason behind JunoCam is to get the amateur astronomer community participating in selecting what parts of Jupiter the camera should be snapping pictures, and of processing the raw images.  The image below was captured by JunoCam during Juno’s 3rd swing around Jupiter at a distance of about 37,000km.  The south polar region is on the left.

Jupiter - December 11, 2016 JunoCam - Juno Spacecraft

NASA, JPL-Caltech, SwRI, MSSS; Processing: Damian Peach

The above was the PeriJove3 encounter (3rd pass), and voting on the next PeriJove4 will take place between January 19th and 23rd 2017.  This is where the community can propose and vote for Points of Interest to photograph with JunoCam during the rather quick (2 hours) close pass with Juno.  You can even submit images of Jupiter taken with your equipment to help plan the Points of Interest.

Ref: JunoMission

NASA Juno Mission Trailer: JOI

Video

Space-thriller themed mission trailer

Secrets lie deep within Jupiter, shrouded in the solar system’s strongest magnetic field and most lethal radiation belts. On July 4, 2016, NASA’s Juno spacecraft will plunge into uncharted territory, entering orbit around the gas giant and passing closer than any spacecraft before. Juno will see Jupiter for what it really is, but first it must pass the trial of orbit insertion. For more information: http://www.nasa.gov/juno and http://missionjuno.swri.edu

It’s GO for the Thirty Meter Telescope (TMT)

We all have aperture fever, not just us crazy backyard astronomers, and with the latest announcement from the Canadian Government to provide nearly $250 million over 10 years, we should see the TMT operational in 2023-2024.  When completed it will be the largest telescope, until the Europeans have their European Extremely Large Telescope (E-ELT), also set for first light in 2024.

Thirty Meter Telescope - Courtesy TMT International Observatory

Thirty Meter Telescope – Courtesy TMT International Observatory

The telescope optical design is a folded Ritchey-Chrétien. Both the primary and secondary mirrors are hyperboloidal, and together they form a well-corrected focus. The tertiary mirror is used to fold and steer the light path so that the science beam can be delivered to any of eight instruments that will be mounted on the two main Nasmyth platfoms. The image is formed 20 meters from the center of the tertiary mirror. The focal ratio of the telescope is f/15.

The field of view of the telescope is 15 arc minutes (fully illuminated), or 20 arc minutes with slight vignetting at the edges of the field. At f/15, the focal length of TMT is 450 meters (1476 feet)! This means that the 20 arc minute field of view measures 2.618 meters (8.6 feet) in diameter.

The primary mirror focal ratio is f/1. This short focal ratio was chosen to make the telescope compact, which helps to keep the telescope structure and the enclosure affordable. As the name implies, the primary mirror is 30 meters (98 feet) in diameter, and because it is f/1 it has a focal length of 30 meters.

Current king of the largest light-bucket is the 10.4m diameter Gran Telescopio Canarias.  Therefore the 30m TMT and the 39m E-ELT will be a considerable gain in light gathering power over the current crop of telescopes.  Some are predicting that scientists will be able to directly observe planets orbiting distance stars, and perhaps even see distant oceans and weather formations.

It’s always intrigued me how we spend so much on EQ mounts, when these large telescopes operate in a simpler Alt-Az configuration.

Sources: CBC, TMT