Stelliferous: Geminid meteor shower, and the launch of the James Webb Space Telescope – Sarasota Herald-Tribune

Howard Hochhalter| The Bishop Museum of Science and Nature

Did you everthink about the factthat astronomy is a sciencethatdeals with what was rather than what is?

Seriously.Lets sayan astronomer trains a telescope tonight atthe Andromeda Galaxy, the closest galaxy to our own Milky Way. The Andromeda Galaxy is 2.5millionlight-years away,andalight-year is how far light travels in one year (5.87 trillion miles), sothe lightfromthe Andromeda Galaxy that our astronomer seestonightleft that galaxy 2.5 million years ago, about the time early hominids started using stone tools.

Even an astronomical event that happens in the present, such as a meteor shower, is a trip to the past.

Take theGeminidmeteor shower, which reaches its peak the nights of Dec. 13 and 14.

Most meteor showers occur when theEarth plows through debris left by a comet. When those cometary bits and pieces, usually the size of a grain of rice, hit the atmosphere,they burnup and create what some people call falling or shooting stars. The parent of OctobersOrionid meteor shower, for example, is the famous comet Halley.

The parent of the Geminids, however, is an asteroid called 3200 Phaethon. As it approaches the sunin its 1.7-year orbit aroundit, chunks of the asteroid break off to become the meteors of the Geminids as they rip through Earths atmosphere at 79,000 mph.

Producing up to 150 meteors per hour, including the occasional fireball, the Geminids were first recorded in 1833so meteors you see during this monthsshower might be from 3200 Phaethons first appearance in our part of the solar system, 188 years ago, or they might be from the asteroids most recent visit, in 2020. In any case, youre looking into the past.

Meteor showers are named for the constellation from which they seem to radiate (its called the radiant), and, for the Geminids, thats Gemini, which rises a little after 9 p.m. Nov. 13.

A waxing gibbous moon, 75% illuminated, will wash out meteors for much of the night, but it will set at2:25a.m. Dec. 14, while Gemini is still high in the sky, which means youll have good viewing until civil twilight at 6:47 a.m.

Our final iteminvolvesa tripwayback into the pastalmost to the beginning of time.

On Dec.18, the $10 billion James Webb Space Telescope, a collaboration between NASA, the European Space Agency and the Canadian Space Agency,will blast offaboard an Ariane 5 rocketfrom the Guiana Space Centre in Kourou, French Guiana, on a mission that will look more than 13 billion years into the past and allow us to see light created just after the big bang.

For anyone interested in astronomy, this is a very exciting mission, one that is expected to surpass even theaccomplishmentsof the Hubble Space Telescope, which are many.

For more than 30 years, weve marveled at the mesmerizingly beautiful imagesHubblehas sent back to Earthand at the advances in our understanding of the universe the telescope has provided.Hubblehas made more than 1.9 millionobservations, and its data havebeen the source of more than 18,000 scientific papers, which, themselves have been cited inalmost 1 million otherpapers.

The worlds most brilliant astronomers do miracles with this observatory, said David Leckrone, former Hubble senior project scientist. And it just keeps going on and on and on, and my jaw keeps dropping lower and lower with each new discovery.

And, according to NASA scientist Michelle Thaller, Theres not a single astronomer in the world whose life hasnt been touched by Hubble.

So, whysuch high expectations forthe Webb Space Telescope?

Lets compare thetwo telescopes.

Size: When it comes to reflecting telescopes, the bigger the mirror, themore lightit gathers(in other words, the more it cansee).Hubblesmirror is 7 feet, 10 inches. Webbs mirror is 21 feet, 4 inches.

What Webb and Hubble see: While both telescopes operate in the visible spectrum (that is, they can photograph objectsvisible to humans),Webb will be able to see farther into the infraredportionof the spectrumthan Hubble does. This is important because light from the most distant galaxies (those formed soon after the big bang) reaches Earth as infrared light, and the more infrared light a telescope can detect, the more distant galaxies it will see.

Location: We send telescopes to space so they dont have to deal with manmade light pollution and the blurring effects of Earths atmosphere.Hubble orbits the Earth, atanaltitude of 340 miles. Webb willnot orbit the Earth; rather it will be at a fixed location called the second Lagrange point, or L2, 1 million miles from Earth.

ALagrange pointthere are five of themis aplacein space where the gravitational forces of two large bodies, such as the Earth and sun, cancel each other out, and an object, such as a telescope, can be parked there to make observations. Picture the Earth in its orbit around the sun; now, draw a straight line from the center of the sun through the center of the Earth, extendingto a point1 million miles past Earth. Thatis L2.

So, the Hubble telescope orbits the Earth, passing between the Earth and sun and between the Earth and moon,its observations affected by light from the sun, Earth and moon,buttheWebb telescope will always be on the oppositeside of the Earth from the sun, pointing its giant mirror out into the depths of space.Further, apolymershieldthe size of a tennis court will block all light from the sun, Earth, and moon, insuring a constantly dark sky for the telescope to peer into.

It will take roughly 30 days for Webb to reach its orbit at L2, then, after six months of checkouts and calibrations, its science mission will begin.

We can only wonder what its first images will be.

Astronomy by the Bay:TheBishopwill provide telescopesso you can observethe waxing gibbous moon andthe planets Venus, Saturn and Jupiter, which will be lined up like a string of pearls along the ecliptic in the western sky.And, yes, were still lookinginto the past:Venus, the closest of our three planets,is almost 60 million miles from Earth right now; thats more than five light minutes away, so the light youll see when you look at Venus left the planet five minutes before you see it. The event is freebut registration is required.(Dec. 14, 5:30 p.m. to 7 p.m., The Bay Park, 777 N. Tamiami Trail, Sarasota)

How to Use Your Telescope: Need some help figuring out how to use your telescope? Meet us out at Robinson Preserve and we will help you figure it all out! Dont forget to bring your telescope with you! The session is free but group size is limited and registration is required. (Dec. 18, 4:30-5:30 p.m., Robinson Preserve, 10299 9th Ave. NW, Bradenton)

Stelliferous, featuring the Star of Kings:This star has been a popular topic at planetarium shows since the 1940s,aspeople explore astronomical explanations for the star described in the nativity story. Was it a comet, a supernova or something else entirely? JoinmeinThe Planetarium,where welltake a journeyback in timeto what was really happening in the skies some 2,000 years ago. Cost is $8for members of theDiscoverySociety, $10for all others. (Dec. 22,7 p.m., The Bishop, 201 10th St. West, Bradenton;Dec. 23: Star of Kings will replace our regularly scheduled liveStar TalkinThe Planetarium. 12:15 p.m. Included in the price ofMuseumadmission.)

For further program details and registration, visit BishopScience.org/events.

Howard Hochhalter isdirectorofThe PlanetariumatThe Bishop Museum of Science and Nature. Each month, he hostsStelliferous, a live discussion at the Museum of whats happening in our night skies and in the world of astronomy. VisitThe Bishoponline atBishopScience.orgto register or to learn about other events and activities at the Museum.

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Stelliferous: Geminid meteor shower, and the launch of the James Webb Space Telescope - Sarasota Herald-Tribune