At least 3 planets of TRAPPIST-1 system may contain Earth-like atmospheres: Study
Wednesday 07/February/2018 - 11:41 AM
At least three out of the seven planets of the TRAPPIST-1 planetary system might contain Earth-like atmospheres، raising hopes that the 40-light-year away extraterrestrial worlds are likely enveloped in life-supporting air، new study says، according to "Press TV".
A group of astronomers، employing the first spectroscopic survey of these worlds conducted by NASA’s Hubble Space Telescope، made thorough observations of four of these planets، which are orbiting their host star، TRAPPIST-1، within or near the system’s habitable zone، the circumstellar region where liquid water could exist on a planetary surface.
The study، whose findings were published in the journal Nature Astronomy on Monday، revealed that at least three of the observed planets، namely d، e and f، do not seem to contain puffy، hydrogen-rich atmospheres similar to gaseous planets such as Neptune، favoring more compact atmospheres like those of Earth، Venus، and Mars.
The planets have named as b، c، d، e، f، g، and h in order of increasing distance from TRAPPIST-1، which is a dim and ultra-cool dwarf star، roughly the size of Sun’s largest offspring Jupiter in diameter. Researchers are yet not sure of the atmospheric structure of planet h due to the lack of data received by the Hubble.“Hubble is doing the preliminary reconnaissance work so that astronomers using Webb know where to start،” said Nikole Lewis of the Space Telescope Science Institute (STScI) in Baltimore، Maryland، co-leader of the Hubble study.
“Eliminating one possible scenario for the makeup of these atmospheres allows the Webb telescope astronomers to plan their observation programs to look for other possible scenarios for the composition of these atmospheres،” she added. Water worlds!
Meanwhile، a separate study conducted by researchers from the European Southern Observatory (ESO) revealed that some of these rocky planets could contain more water than even the oceans of the Earth—up to 250 times more.
The study، whose results were published in the journal Astronomy & Astrophysics on Monday، said that at least five of the planets contain up to 5 percent water. In comparison، our cosmic home’s oceans account for just 0.02 percent of the Earth’s mass، despite covering about 71 percent of its surface.
Simon Grimm، an astronomer with the Center for Space and Habitability at the University of Bern in Switzerland، said that planets d and e “are the most likely to have liquid water on them.”
Water on the hot innermost worlds b and c is probably “gaseous،” he added، vapor drifting in the atmosphere. Water on the cold outermost planets f، g، and h is expected “in the form of ice.”
Astronomers are particularly intrigued by TRAPPIST-1e، the most Earth-like of the family، which “receives the same amount of energy from its star that Earth receives from the Sun،” Grimm further noted، adding، “It has the best scenario for life.”
All seven planets، located in the constellation Aquarius، are likely to be tidally locked، meaning that each one has a permanent dayside and a perpetual nightside، making the development of life on them much more challenging. Regardless of the appalling distance from Earth، some 229 trillion miles، we might be eager to know that، using our current space technology، how long it would take to reach the present location of this alien solar system. The calculation is not complicated. You can simply determine the total time needed to reach there by dividing the distance to TRAPPIST-1 by the spacecraft's speed.
The fastest spacecraft ever launched، NASA’s New Horizon spacecraft، which flew past the dwarf planet Pluto in 2015، is currently dashing out of our solar system at about 32،000 miles per hour. Traveling with this speed، it would take the New Horizon some 817،000 years to reach TRAPPIST-1 and its offsprings.
NASA's Juno spacecraft، which has a mission to study Jupiter، attained a top speed of about 165،000 miles per hour، using its massive gravity، for a period of time، when it approached the gas giant in 2016. To reach the dwarf star with this spacecraft، providing that Juno constantly travel that fast، we must wait some 159،000 years before we visit the alien planets.
But how about traveling with NASA’s space shuttle، which orbits our planet at a maximum speed of about 17،500 miles per hour? We will reach TRAPPIST-1's current location some 1.5 million years later if we travel with the speed of this spacecraft.