By Benjamin Vermette
Discovery of 3 potentially habitable planets
Some look for life in the ocean, others look for it deep down into the earth. Some even look for life in their own soul, in their hearts, and others look for it on exoplanets tens of light-years away from home.
On May 2, a team of Belgian astronomers published their discovery of three Earth-like planets orbiting an ultracool dwarf star named TRAPPIST-1. That’s a big deal. They are the first planets to ever be discovered orbiting that particular kind of star.
But the most exciting thing of this discovery is that the planets are so close to us! Only 40 light-years away! That makes them subject to unprecedented studies and observations.
The Belgian TRAPPIST telescope discovered these celestial bodies as they passed in front of the star, and the fact that the star is relatively faint will make the observations easier.
Typically, when a new planet outside our solar system is discovered, it is much bigger than Earth, it is much farther away than these three newcomers and it orbits much brighter stars. But these recently located planets don’t respect any of these criterions! That’s what makes them special and interesting for science investigations.
“These are the first planets similar in size and temperature to Earth and Venus for which we can study the atmospheric composition in detail, and really constrain the surface conditions and habitability,” said lead author Dr. Michaël Gillon from the University of Liège.
However, at first glance, these planets may seem to have nothing special. Perhaps they even seem 'scientifically irrelevant’. TRAPPIST-1B and TRAPPIST-1C, as two of the three planets are dubbed, have a revolution period of respectively 1.5 and 2.4 Earth days, which means they perform one complete revolution around their sun in a very small amount of time. As Kepler’s laws told us, the closer the object is to the other, the faster it orbits. Following this logic, this means the planets are very close to their sun, so they’re very hot, right?
Almost. Yes, they orbit very close to their mother-star, but this one is really cold! When I say really cold, I mean it has surface temperatures of only 2,277 degrees Celsius. So the planets are probably not ‘inferno’ worlds.
TRAPPIST-1D has years lasting a more reasonable amount of time – however very uncertain – than its two brothers: 4.5 to 73 Earth days.
The closest planets receive as much as four times the amount of radiation we receive here on Earth, which makes them on the limit of what scientists call the ‘habitable zone’. The outermost one seems to be doing just fine in terms of radiation.
Because of this, the temperatures on these objects might vary from slightly higher than water’s boiling point and a lot below freezing.
However, being uncertain that these planets are solid, scientists tell us that the star, TRAPPIST-1, is rich in heavy elements, which suggests that they might in fact be rocky planets.
As an ultra cool dwarf star, TRAPPIST-1 is very stable: they won’t change for tens of billions of years, which provides a suitable environment for life to grow on its planets.
“Why are we trying to detect Earth-like planets around the smallest and coolest stars in the solar neighbourhood?” Dr. Gillon said in a statement. “The reason is simple: Systems around these tiny stars are the only places where we can detect life on an Earth-sized exoplanet with our current technology. So if we want to find life elsewhere in the universe, this is where we should start to look.”
Hubble’s successor, the James Webb Space Telescope, currently under construction and to be launched by 2018, might revolutionize the search for life. It potentially has the capacity to detect biological molecules in other planets’ atmospheres!
Russian billionaire Yuri Milner and Prof. Stephen Hawking’s dream
What happens when you put a Russian billionaire and one of the world’s most brilliant scientists in the same room? Not only do you get an ambitious research project, but you also get some money to fund it.
Milner’s project, named “Breakthrough Starshot”, was introduced at the One World Observatory in New York in mid-April. Endorsed by renowned-physicist Stephen Hawking, Breakthrough Starshot consists of a $100-million research and engineering program that will eventually allow sending space probes to the nearest star system, Alpha Centuri. More precisely, the project seeks to create ‘chip’ devices that can travel at 20% the speed of light, take marvellous pictures in empty space, as well as being extremely small.
A gigantic laser beam here on Earth will provide the necessary thrust to these high-end devices so they can travel the 4.37 light-years separating us from Alpha Centuri in about 20 years. Since the ‘chips’ are designed to carry a sail on their back, the photons from the light beam will be enough to power them through interstellar space.
At this rate, these spaceships would get to Pluto in about 24 hours! A trip that took humankind’s fastest spacecraft yet, New Horizons, more than 9 years!
The cool thing is that those relatively cheap spacecraft could be deployed not only once but multiple times, to ensure that Russian billionaire Yuri Milner and Prof. Stephen Hawking’s dream come true, to ensure that humans finally reach the stars for the first time.
SpaceX made the news again
On April 27, hours after it revealed a plan to send a commercial mission to Mars in 2018, SpaceX was awarded an $82 million contract to launch a government GPS satellite.
This contract is the first competitively sourced National Security Space launch services contract in more than a decade.
The satellite, GPS III, will be the second of its kind to ever be sent in orbit, as it is planned to launch from Cape Canaveral Air Force Station, Florida, in May 2018. It is a high-tech Global Positioning System, as it is expecting to meet the increasingly higher needs of both military and civilian users. It is equipped with a special anti-jamming system as well as with the common L1C signal, which is compatible with many other global navigation satellites.
SpaceX winning this contract means that they have eliminated the monopoly that United Launch Alliance (ULA) had on military space launches for nearly a decade.
However, note that ULA didn’t compete for the GPS III launch contract, saying they had accounting issues, problems with the imports of their Russian-made rocket engines, and according to rumours, problems with SpaceX’s low fees.
"This GPS III Launch Services contract award achieves a balance between mission success, meeting operational needs, lowering launch costs, and reintroducing competition for National Security Space missions," said Lt. Gen. Samuel Greaves, Air Force Program Executive Officer for Space.
The $82.7 million contract supports the rocket production, launch procedures, mission planning, and spaceflight certification.
Supporting SpaceX means supporting Musk. Supporting Musk means supporting ambition. And this is yet another step towards Mars.