This image is a tiny fraction of the Large Magellanic Cloud. The cloud is not in our galaxy, the Milky Way. It is orbiting our galaxy, along with 12 or so dwarf galaxies. If we lived on a planet in the Large Magellanic Cloud, we would see the Milky Way galaxy up in the sky at night, fanning out before us, as large as 70 moons across. Perhaps we would know ancient folk tales about what it might be.
Many people do not know that we have dwarf galaxies orbiting our galaxy. The Large Magellanic Cloud was, a long time ago, a properly-shaped galaxy, only far smaller than our own. It’s collisions and gravitational interactions with other galaxies in our little pack have pulled it apart, spreading gas and dust to coalesce into the most active star forming region in our entire local group of galaxies.
Our local group of 30-some galaxies has another big player besides the Milky Way. The Andromeda galaxy is actually larger than our own, though our Milky Way may have more mass. We’re a tightly-knit family here, gravitational bound together and spanning 10 million light years.
Before our sun burns out, in a few billion years, our galaxy will collide with the similarly massive Andromeda galaxy. From now on, we will see Andromeda growing larger and larger in the night sky. Eventually, the sight of Andromeda in our skies will be awe-inspiring — literally filling the night sky.
We will notice stars bursting into life all across the night as new gravitational forces cause interstellar clouds to collapse and ignite. For millions of years we will collide, passing like ghosts through one another, through the vast distances between all stars. Eventually, the supermassive black holes at the center of each galaxy will merge in a monstrous event.
But this is about the Hubble Space Telescope, and the Large Magellanic Cloud, our “little” neighbor, only 170,000 light years away. The image at the top was taken just two days ago by Hubble’s Wide Field Planetary Camera 2. It was taken in celebration of Hubble’s 100,000th orbit around the Earth. The nicer, very high resolution camera is currently broken. And the camera that just took that picture will be replaced by the Wide Field Planetary Camera 3.
The Wide Field Planetary Camera 2 was installed on the first Hubble service mission in 1993. This was the same mission that Hubble’s “glasses” were installed to correct its near-sightedness. These corrective lenses, called COSTAR, will be removed on the upcoming shuttle servicing mission. This will free up a science module slot in Hubble, making room for the Cosmic Origins Spectrograph instead.
This fifth and final mission to service Hubble is STS-125, scheduled to launch October 8th. Hubble will no longer need its “glasses” after this mission because all the newest instruments have corrective optics already built into them. And, with COSTAR gone, it will be the first time that Hubble will be operating at full capacity since it arrived in orbit. Hopefully, the astronauts will be successful with all their tasks, particularly the tasks that were never supposed to happen, such as the individual extraction of circuit boards and detailed component replacements, outside the modular designs.
Whomever pays attention to shuttle missions will have noticed how the crew and ground inspects the vehicle’s exterior in painstaking detail immediately upon settling into a stable orbit. If damage is found that cannot be repaired with a space walk, the crew will fly over to the space station and hang out until a rescue vehicle is sent.
The Hubble mission is a little different, however. Hubble orbits more than 100 miles higher above the earth than the space station. Its orbit is at the furthermost reaches of the shuttle’s capabilities. As such, if the crew discovers irreparable damage, their only recourse is to lower power and food consumption while waiting for a rescue. They should be able to camp out for 25 days or so, if they don’t start throwing each other out the airlocks before that.
But if all goes well, and they have enough fuel, the crew will attempt to boost Hubble’s orbit as far as they can to help prolong Hubble’s life. They hope to give a boost of up to 10 miles and several years. And when all is done with this mission, Hubble will hopefully continue its observations for us until at least 2013, when the James Webb Space Telescope will take Hubble’s place as the premier space-based telescope.
And James Webb, well, his mirror is 6 times a big as Hubble’s. He won’t be stuck here at home, either, so close to Earth which shines so brightly, and the sun glaring, all the time… James Webb will be traveling out away from the Earth and away the sun, far past the orbit of the moon, about 1.5 million miles until it reaches the L2 Sun-Earth Lagrangian Point. That’s the gravitational sweet spot that allows James to orbit the sun along with the Earth’s orbit, so that the Earth is always blocking out the sun.
James will be joining the Wilkinson Microwave Anisotropy Probe at L2, which recently mapped the background radiation of the universe and determined that the universe was 13.7 billion years old. We have many different techniques all agreeing on 13.7 billion years now. Wilkinson also determined that only 4.6% of the universe is made of baryonic matter (atoms and molecules) — the matter we see in everything as dust, stars, our bodies — everything visible and tangible. While 23% of the universe is made of “dark matter” which we cannot yet see or sense in any way, and 72% “dark energy“, which we also have no idea about, other than it’s causing the galaxies to fly away from each other faster and faster.
Oh, and also in October, Europe will be launching the Planck Satellite to L2 which will further the work of Wilkinson in greater detail. L2, at last, is turning into quite the crowded little physics playground. And it’s all because of Hubble.
The man, too. Edwin. He was looking at some of the “stars” outside of the plane of the Milky Way we see at night. He got the wild idea that maybe some of those weren’t actually stars. Maybe they were whole other galaxies, super super far away — galaxies as huge or even bigger than our own Milky Way, and each of them, having billions of stars like our own, all clustered together. That was in 1919. Until then, we thought that the Milky Way was all there was — as if our galaxy was the entirety and center of the Universe. But Hubble blew our minds — and we today, take his insight for granted.
Much like Copernicus, back in 1530, who claimed that the Earth rotated on its axis and revolved around the sun. But Nicolas was too frightened to say it too loudly. But an Italian scientist named Bruno believed him, and shouted it out for all to hear. He was burned at the stake in 1600 by the Christians. But soon after, the loudmouth Galileo took up the torch, and in 1633 was forced to recant his belief in the Copernican notion of the sun being the center of our solar system, and was subsequently imprisoned in his own home for the rest of his life. But, the cat was out of the bag now.
Hubble knows the Universe is much older than what many Christians claim is possible, based upon the Bible. But not all Christians. And Hubble knows everything came from a “Big Bang”. The Vatican actually has several astronomical observatories now. And thankfully, Edwin wasn’t burned at the stake. Many more educated Christians actually like the Big Bang model, because it makes everything spring into existence somehow at a single origin point, as if God just decided to go ka-pow!
And then, there we have it.
I remember a few years ago Justin writing to me, upset that we were letting Hubble just die after all it had done. I told him I wasn’t too upset about it, because James Webb was coming right behind, not to mention other space-based observatories like Spitzer, Chandra and Compton. And those are just a drop in the bucket now.
But Hubble can see light frequencies within our humanly visible spectrum. James Webb will only see infrared light. But that’s ok. We’re just a little prejudiced. Light, or the electromagnetic spectrum, travels across a great range of frequencies, and our eyes only can perceive the tiniest fraction of the light that constantly rains down upon us. And light in the infrared frequencies can pass through many obstacles without being hindered. So, we can actually “see” a lot more.
But not really — we have to convert the infrared light detected into “fake” colors that we can see. It was actually Sir William Herschel who discovered this “invisible” light, back in the 1700’s. A little strange, since he was mostly an accomplished musician. But he liked building telescopes, too. During some play with a prism where he was separating light into its frequencies, he tried measuring the temperature of the room by placing a thermometer just to the right of the red. Oddly, it was hotter there, with apparently no light, than in the red. Oh, and he also discovered the planet Uranus, and several moons.
Which reminds me, there is another space observatory heading to the Lagrangian 2 party along with Planck, Webb and Wilkinson — Europe’s Herschel Space Observatory. This observatory will be looking out with eyes that see through the full far infrared and submillimeter wavelengths.
Within the next few months though, with some luck and a lot of skill, we should be seeing some amazing new sights from Hubble, as it receives technology from our current decade to replace it’s less capable and failing systems. In fact, the improvement should be dramatic.
But in a sad necessity of what is to come, the shuttle crew will also be installing a soft docking clamp on Hubble during their repair mission. This clamp is meant to allow a small robotic craft to dock with Hubble, then pull it downward to the Earth. After all, we don’t want giant globs of molten glass and metal falling out of the sky just anywhere. We should protect against stuff like that… Or shoot each other. Who’s to say?
Images Credits: NASA, STSCI