Tonight (Tuesday August 11, 2015) will be first of several good nights for the year's most active meteor shower watching. Each year around this time, as the Earth makes its annual trip around the sun, it passes directly through the path of comet Swift-Tuttle. Though the Earth makes its trip around the sun once every 365 days, Swift-Tuttle's takes 133 years, and the most recent time it passed through this portion of the solar neighborhood was back in 1992.
The meteor shower itself is composed of remnant bits of the comet that were jettisoned during one of its previous trips as it was heated up by the sun. Those bits continue to float around along its path until they collide into the Earth's atmosphere. When this happens, they heat up from all of the friction, and then burn up - causing the streaks of light that dissipate within about a half second.
Now you may be wondering - if the Earth crosses the path of the comet, then is there some potential that the two will collide? In fact there is, however scientists have been able to calculate that the soonest this could possibly occur is in 4479. I'm not planning to stick around long enough to witness this, but maybe someone reading this will. Even then, calculations show that the chance of there actually being a collision are pretty low, or .0001% - that's one-ten-thousandth of a percent. Until then, like clockwork, glance up into the evening sky around the second week of August and enjoy the free light show.
The Universe is Dying
Well, not anytime soon anyway.
Researchers announced yesterday that the Universe has been losing total energy, and specifically that older stars are going out faster than new ones are being born. Their observations are based on the intensity of light omitted from multiple regions of space. Light that was observed from the deepest, oldest portion of the Universe (about 2 billion years old) has the intensity of about 19 million suns, whereas that from more recent sections only has the intensity of 11 million suns.
What does this mean for our corner of the Universe? Nothing in our lifetime, or even possibly the lifetime of humans on Earth. But someday, if you were to observe the Universe as we see it now, there will be far fewer stars to be seen in the sky. However, that may take a hundred-trillion years; long after this solar system has been put to rest.
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