The crew of STS-125 performing spacewalks to repair Hubble in 2009 (Photo courtesy:STScI)
If you happen to be stretched out on a meadow somewhere in the wilderness and you stare up at the star-studded sky or if you stop at a layby on the Trans-Canadian Highway to stretch your legs and just stand there a while, your hands gripping the pre-formed galvanised steel traffic barriers with bright orange stripes that they have on bends, or if you are in any place that doesn’t have too many lights around, you will see it streaking across the skies.
If it happens to be sometime around two hours before dawn or two hours after sunset, you’ll see it as a very bright dot of light. Those viewing hours ensure that you’re in the shadows while that object in the heavens is bathed in sunlight.
The object is school bus sized and covered with reflective bright gold insulation with large solar panels that also reflect sunlight. All these reflective surfaces make the object sometimes seem as bright as Venus in the evenings and difficult to miss.
As your eyes follow the object’s progress across the night sky, it takes around a minute and a half to traverse your field of vision and disappear beneath the horizon, only to come back up again after 96 minutes. Ever since it went into orbit in 1990, this thingy has gone around more than 136,000 times and covered over 3.9 billion miles, the equivalent of a trip to Neptune.
To a space buff like me, that object is undeniably the single most significant and spectacularly successful space venture, after the Apollo program. It has held the people of the world captivated by the amazingly clear images that it has sent back to us, of sparkling galaxies and dust clouds that are billions of light years away.
By far the most iconic Hubble photo is The Pillars of Creation, within the Eagle Nebula, 7000 light-years from us. They are so named because the gas and dust are in the process of creating new stars. This pic was named one of the top ten Hubble photos by the scientists at the Space Telescope Science Institute (STScI). The pillars are composed of cool molecular hydrogen and dust, the one on extreme left about four light years in length. Those finger-like protrusions at the very top of the clouds are larger than our solar system. I guess it takes a lot of gas to build a solar system. (Photo courtesy: Astronomers Jeff Hester and Paul Scowen, Arizona State University)
It is aptly named too – Hubble Space Telescope (HST), after the brilliant 20th century astronomer, Edwin Hubble, who for the first time proposed that the universe is expanding and that objects that are furthest from us are receding away at faster and faster speeds. By the same argument came the realization that if we could look far enough, we would actually be looking at the universe as it was just after the Big Bang.
But the HST didn’t begin transmitting those breathtaking pictures right away. As soon as it settled into orbit and trained it’s eye on the skies, scientists operating the telescope discovered that its 2.4-meter diameter mirror had a flaw that they determined to be a spherical aberration. The mirror was perfectly polished, but to the wrong specs. As a result, the pictures that came back were blurry, not the exquisite images of distant galaxies that scientists had been dreaming about for years.
Fortunately, the Hubble had been designed to allow servicing and upgrades while in operation. A geo-stationary orbit at 30000 miles or further would have been ideal but the HST had been placed in low earth orbit, just 289 miles above the earth, so that Shuttle missions could access it and space-walking astronauts could work on it.
Finally, a December 1993 Space Shuttle repair mission put ‘eyeglasses’ on the poor dear and voila! Suddenly the world was looking at photos of creation, galaxies so distant that they might have been that way, within just a million years from the Big Bang.
Now after exactly 25 years of sterling service, its mission extended repeatedly by no less than five service calls, the HST is gradually winding down and the planning for the her eventual demise has begun. NASA is getting ready to allow Hubble to re-enter the earth’s atmosphere and burn up, sometime around 2020.
The Hubble Telescope has revealed a universe that is dynamic and explosive and left even the most experienced astronomer stammering,’ Gosh, I never it was like that!’ It has captured paired galaxies that look like reluctant partners in a high-school social, trapped together by their own gravitational pulls and forced to do a tap-dance together, until the bigger one eventually swallows up the other. It has sent back infra-red images of quasars – eerie supernatural beings that are suspected to be super-massive black holes – venting jets of hot gases and x-rays thousands of light-years into space. It has transmitted scenes of stars self-destructing in massive supernova fireballs several light-years wide, comets hitting the surface of Jupiter, Saturn and it’s awesome rings and it’s giant orange moon, Titan, casting a long shadow over it’s north pole while it’s kid brothers, Minas and Enceladus, scurry to keep up with it.
The HST has brought alive virtually every science fiction space fantasy imaginable, in stark, clear and crisp images, leaving all of us enthralled, amazed and above all, humbled. By enabling us to see far beyond even the farthest galaxies, it has allowed us to see far back into our past.
But still not far enough. The thirst to find out if we did or didn’t actually come from Adam and Eve is an overpowering emotion. We are getting ever closer to the question about the very existence of the Almighty as stated in the scriptures – a stand-alone and all-pervasive creator. If He truly exists, then He has given us the brains to figure it all out. He actually wants us to come up to Him and touch Him and say hello. He is lonesome maybe. The Hubble is just one of those significant steps that mankind has taken in the search of that truth.
Hubble now has a successor – The James Webb Space Telescope (JWST), under construction and scheduled for launch in October 2018, atop an Arianne-5 heavy lift launch vehicle of the European Space Agency.
The JWST will offer unprecedented resolution and sensitivity in an order of thousandths, when compared with the quality of the Hubble images. It will sport a 6.5 meter primary mirror which will make the Hubble look like one of those dinky telescopes you get at Toys-r-Us. It will also be much larger (about the size of an 18-wheeler tractor trailer when it’s sun-shield is unfurled) and unlike the Hubble, it will be parked at a Lagrange Point. Here is how I understand a Lagrange Point…….
The James Webb telescope, orbiting an imaginary Lagrange Point. Every moon-bearing planet in the Solar System has multiple Lagrange Points. In the Sun-Earth-Moon system, there are five, L1 to L5. The Sun’s mass is so dominant that it can be treated as a fixed object and the Earth-Moon combo then becomes a two-body system. 18th century mathematicians, Leonhard Euler and Joseph-Louis Lagrange, discovered that there were five special points in this rotating reference frame where a gravitational equilibrium could be maintained. That is, an object placed at any one of these five points in the rotating frame would stay there, it’s position fixed with respect to the others, the multiple pulls from the others cancelling out. Such an object would then orbit the Sun, maintaining the same relative position with respect to the Earth-Moon system.
The Lagrange Point L2 is where the James Webb Space Telescope will be parked, pirouetting round it in a tiny circular orbit as shown in the previous diagram. The L2 is in line with the Earth and the Sun, at a distance of 1.5 million kms from us. Usually an object circling the Sun further out than the Earth would take more than one year to complete its orbit round the Sun. However, the balance of the gravitational forces at the L2 point will make the JWST keep up with the Earth as it goes around the Sun. It will take relatively little rocket thrust to keep the spacecraft in orbit around L2
The moment the Hubble’s first phenomenal images started being published, it morphed from just another scientific gobble-dee-gook on which billions of dollars had been needlessly thrown away to a rock star among observatories and a huge public relations coup for both, NASA and it’s partner in Hubble, the European Space Agency (ESA). Everyone, all over the world, from little school kids to ageing has-beens (like yours truly) gaped open-mouthed. Overnight the media dubbed it The People’s Telescope.
The name of the James Webb Space Telescope is not yet known as widely as the Hubble’s and probably will never be, unless it sends us pics that are many times more breathtaking in our laymen’s eyes, than the Hubble’s. But I do hope that I shall be alive and discerning enough to be able to make that judgement.
Meanwhile, I recently came across a term for folk who are crazy about the Hubble Telescope and it’s awe-inspiring output – Hubble Hugger. I understand that there are millions of Hubble Huggers all over the world.
Excuse me, it’s 4 am, the skis are clear and I have to go hug a hubble. This is her Silver Jubilee anniversary year.