Today ESO has announced the discovery of a Proxima b, a planet orbiting Proxima Centauri, the star nearest to our Sun, sparking the imagination of interplanetary travel enthusiasts: will really be reached for the first time a planet outside the Solar System?
Let’s start Shots: Proxima Centauri is from us “just” 4.23 years light. A light year is the distance light travels in a vacuum in a year, or about 9.5 trillion km, then The new planet is about 40 trillion kilometers from us . For comparison, Neptune, the last planet of the Solar System, is from the Sun about 4.5 billion kilometers. Compared with the distances with which we deal every day, that of Proxima b is certainly huge, but in astrophysics this distance is quite ridiculous: as it is the nearest planetary system to our instantly became the number one goal of a potential expedition from Earth to an exoplanet.
How long will it take to achieve it?
In their article in Nature, the authors of the discovery of the planet do not exclude that in the coming centuries a robotic mission could leave with route to Proxima b, but how long will the journey? In order to speak of time to reach Proxima b we talk about speed, but we must first clarify a point in this regard. The speeds are not absolute, they must be referred to something. This is the reason why you’ll often find very different speed when it comes to both space speed.
In our daily life we do not usually doubt that we take as a reference any point “fixed” fixed to the Earth. Instead as we measure the speed of the spacecraft? If you need to reach destinations not far from our planet (like the Moon), you can still use the center of the Earth as a reference, but for longer-range missions, things are more complicated. If you measured the speed of the spacecraft relative to the Earth, this would be dominated by the rate at which the Earth revolves around the Sun (on average just under 30 km / s, ie just over 100,000 km / h).
A landmark much more useful for interplanetary travel is the sun. Using this reference, the fastest ever built by man was the probe Helios-2 , which over the years 70 has reached our star to record speed of over 250,000 km / h. If a hypothetical mission to reach Proxima Centauri would take a similar speed more than 18,000 years to reach its destination.
But there is to be noted that it is much easier to move to the Sun rather than beyond the boundaries of the Solar System, given the intense gravitational pull that the star exerts, so it will be difficult to reach that speed using the same technology . latest spacecraft directed towards the outer regions of the Solar System (as Juno and New Horizons) have not even approached the speed during their trip.
The San Francisco Rush Breakthrough project, both ambitious and difficult to implement, aims to build nano extremely small probes and read, accelerated by a powerful laser positioned on the ground, according to the plans may even reach a speed equal to one-fifth the speed of light in vacuum. This means that it would take five times the time required for light to reach Proxima Centauri starting from the Earth, that is a little over 20 years.
The man will ever visit the planet?
So far no human crew reached the Solar System planet and projects to form a mission to Mars are still far from realization. There will therefore be a long time before you can think of to bring the first man on Proxima b. Is this idea feasible?
The first hurdle is that your only option currently on the horizon to reach Proxima Centauri in a short time, Breakthrough Francisco Rush , requires the use of microscopic spaceships that will have an on-board instrumentation very limited, let alone the possibility of carrying a human crew.
As we have seen, using a spacecraft to the best of current technology would require tens or hundreds of thousands of years to reach its destination, well beyond the duration of human life. The options facing at this point lead us in the domain of science fiction: artificially slow down human vital functions to prolong life (the so-called suspended animation, achievable, perhaps by means of hibernation), or travel to the edge of a generation ship, inside which the astronauts should live and reproduce, so as to maintain a more or less stable population until reaching Proxima b.
In the latter case, leaving aside all the difficulties associated with perennial coexistence of many people in confined spaces and the fact that you should carry the equipment also on the ship (resistant millennia) necessary to enable man to survive throughout the journey and on a planet completely unknown (and perhaps subject to a very strong ionizing radiation), the first men sbarcherebbero on the planet would have never known the Earth.
Unless some brilliant scientist did not invent warp drive, or find out how to make the jump into hyperspace or how to make a wormhole to make interplanetary travel in a short time, for the moment, with current scientific knowledge available to us , the opportunity to visit in person Proxima bo any other exoplanet remains a utopia . Nevertheless man always continue to push the envelope further, trying to overcome the limits that appear insurmountable.
Can we take pictures Proxima b?
Before traveling towards Proxima b we ask, you can shoot from the Earth a planet so far away? Well, certainly not with a common photographic business purpose, but speaking of the most powerful telescopes available to us today available the answer is: “ni.” the distance from us is not a big obstacle in this case: they were photographed much more distant planets, up to 1200 light years.
The problem, however, is that the technique of direct photography of an exoplanet is particularly complicated and generally requires a relatively young planet, then still warm and bright enough, and far enough away from its star. This is because it must be possible to lock with the appropriate tools, coronographs, the light coming from the star so you can view only the planet.
Proxima b is very close to its star, it is 7.3 million kilometers, one-twentieth of the distance between the Sun and the Earth (one astronomical unit). For comparison, the closest planet to the Sun, Mercury, is 0.39 astronomical units. The use of straight photography in the case of the planet around Proxima Centauri so it is currently very difficult. However, the next generation of large telescopes, such as the European E-ELT, may have the angular resolution for to correctly distinguish the star by the planet, so you can view and photograph only the latter.
Moses Giordano is PhD student in astrophysics at the University of Salento, has to his credit publications in the Astrophysical Journal, MNRAS (Monthly Notices of the Royal Astronomical Society) and other prestigious journals, deals with scientific and disclosure a tech enthusiast. His specializations are general relativity, gravitational microlensong, search for extrasolar planets. Collaborates with Tom’s Hardware for the production of scientific content.
Moses Giordano is PhD student in astrophysics at the University of Salento, has to his credit publications in the Astrophysical Journal, MNRAS (Monthly Notices of the Royal Astronomical Society) and other prestigious journals, deals with scientific and disclosure a tech enthusiast. His specializations are general relativity, gravitational microlensong, search for extrasolar planets. Collaborates with Tom’s Hardware for the production of scientific content.
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