In­tro­duc­ing Tess, the seeker of alien worlds

As­tro­nauts are send­ing the lit­tle space­craft to find plan­ets close enough to scru­ti­nise with tele­scopes or for hab­it­abil­ity

The East African - - FRONT PAGE - By DEN­NIS OVERBYE New York Times News Ser­vice

Sea≥ch fo≥ cos­mic ≥eal es­tate be­gins anew, thanks to a lit­tle spacec≥aft

The search for cos­mic real es­tate is about to be­gin anew. No ear­lier than 6:32pm on April 16, in NASA’S frac­tured par­lance, a lit­tle space­craft known as the Tran­sit­ing Ex­o­planet Sur­vey Satel­lite, or TESS, bristling with cam­eras and am­bi­tion, will as­cend on a Spacex Fal­con 9 rocket in a blaze of smoke and fire and take up a lengthy res­i­dence be­tween the moon and the Earth.

There it will spend the next two years, at least, scan­ning the sky for alien worlds.

TESS is the lat­est ef­fort to try to an­swer ques­tions that have in­trigued hu­mans for mil­len­ni­ums and dom­i­nated as­tron­omy for the past three decades: Are we alone? Are there other Earths? Ev­i­dence of even a sin­gle mi­crobe any­where else in the galaxy would rock science.

Not so long ago, astronomers did not know if there were plan­ets out­side our so­lar sys­tem or, if there were, whether they could ever be found. But start­ing with the 1995 dis­cov­ery of a planet cir­cling the sun­like star 51 Pe­gasi, there has been a rev­o­lu­tion.

NASA’S Ke­pler space­craft, launched in 2009, dis­cov­ered some 4,000 pos­si­ble plan­ets in one small patch of the Milky Way near the con­stel­la­tion Cygnus. Ke­pler went on to sur­vey other star fields only briefly after its point­ing sys­tem broke. After nine years in space, it’s run­ning out of fuel.

Thanks to ef­forts like Ke­pler’s, astronomers now think there are bil­lions of po­ten­tially hab­it­able plan­ets in our galaxy, which means the near­est one could be as close as 10 to 15 light-years from here.

And so the torch is passed. It’s now TESS’ job to find those nearby plan­ets, the ones close enough to scru­ti­nise with tele­scopes, or even for an in­ter­stel­lar ro­bot to visit.

“Most of the stars with plan­ets are far away,” said Sara Sea­ger, a plan­e­tary sci­en­tist at the Mas­sachusetts In­sti­tute of Tech­nol­ogy and a mem­ber of the TESS team, re­fer­ring to Ke­pler’s bounty. “TESS will fill in plan­ets around nearby stars.”

Ge­orge Ricker, an MIT re­searcher and the leader of the TESS team, ex­pects to find some 500 Earth-size plan­ets within 300 light-years of here, close enough for a com­ing gen­er­a­tion of tele­scopes on the ground and in space to ex­am­ine for hab­it­abil­ity — or per­haps even in­hab­i­tants.

But there will be more than plan­ets in the uni­verse, ac­cord­ing to TESS.

“TESS is go­ing to be a lot of fun,” Ricker said. “There are 20 mil­lion stars we can look at.” The space­craft will be able to do pre­cise bright­ness mea­sure­ments of ev­ery glint in the heav­ens, he said. “Galax­ies, stars, ac­tive ga­lac­tic nu­clei,” his voice trail­ing off.

Most of the ex­o­plan­ets will be or­bit­ing stars called red dwarfs, much smaller and cooler than the sun. They make up the vast ma­jor­ity of stars in our neigh­bour­hood (and in the uni­verse) and pre­sum­ably lay claim to most of the plan­ets.

Like Ke­pler, TESS will hunt those plan­ets by mon­i­tor­ing the light from stars and de­tect­ing slight dips, mo­men­tary fad­ing in­di­cat­ing that a planet has passed in front of its star.

The mis­sion’s plan­ners say they even­tu­ally ex­pect to cat­a­logue 20,000 new ex­o­planet can­di­dates of all shapes and sizes. In par­tic­u­lar, they have promised to come up

Newspapers in English

Newspapers from Kenya

© PressReader. All rights reserved.