Astronomically speaking, there have been a number of incredible discoveries announced in the first three months of this year. Perhaps the most important is in Cosmology, the study of the history of the universe. A group using data from an infrared telescope in Antarctica (pictured below) reported stronger than expected evidence for inflation in the first fraction of a second after the Big Bang. Inflation was an idea initially proposed to explain why different parts of the universe look so similar to each other, despite the fact they are so far apart. More technically, the problem is that regions of the universe that should have never been in contact with one another appear as though they were at one point in contact.
In the 1980s an astrophysicist, Alan Guth, proposed an explanation. He speculated that the universe went through a phase of incredibly rapidly expansion. The visible universe we see around us today was actually a part of a small region that grew exponentially in a very short period of time. This rapid growth was predicted to leave a few subtle traces visible in the polarization of the cosmic background radiation – the now cooled energy that remains from the Big Bang. It was these traces that the team found after analyzing the data from Antarctica. If confirmed, this would be another example of a prediction of the Big Bang theory that was subsequently observed. Other examples include the cosmic background radiation, the abundance of Helium, and the age of the oldest objects in the universe.
In February, astronomers working with the Kepler satellite announced the confirmation of 715 new planets around other stars. This brings the total number of confirmed extrasolar planets to just under 1500 with another 3700 awaiting confirmation. Most of these planets are smaller and orbit further from their star – making them harder to detect and thus requiring more time but are more similar to our planet. Four of these new planets are similar in size to the earth and orbit within the habitable zone around their sun – that is, at a distance where liquid water could exist on their surface. The picture above is an artist’s interpretation of two of these planets and shows their relative size compared to earth. Astronomers can now say with some confidence that solar systems similar to ours are common in the Milky Way.
Within our own solar system, scientist analyzing data from the Cassini spacecraft orbiting Saturn have discovered a sea of liquid water beneath the south pole of the ice-covered moon Enceladus. Eruptions from this sea cause the “tiger-stripes” on the surface (visible on the image to the left) and the ice particles result in one of the outer rings of Saturn. This subterranean environment may be hospitable to forms of life similar to those found near deep sea vents under earth’s oceans. Plans for a mission to Enceladus or Jupiter’s moon Europa where a similar ice-covered ocean is suspected to exist may be able to sample ejected water and test for the presence of life.
Clearly our knowledge of the universe and understanding of our place within it increases each year. While eclipses are not a recent discovery, they do offer us an opportunity to gaze up and appreciate the wonders of the nature, much closer to home. Early in the morning of Tuesday, April 15th the entire western hemisphere will be treated to a lunar eclipse. The first full moon after the vernal equinox determines Easter Sunday. This holy week that full moon will pass directly through earth’s shadow causing a lunar eclipse beginning around 2am. The moon will be completely in earth’s shadow between 3:08am to 4:23am. During this time the moon will appear dark red from sunlight refracted through the earth’s atmosphere. The eclipse will end before sunrise. We in the United States have not had a chance to see a total lunar eclipse for a few years. You are welcome to join me and students from Astronomy outside the Dupré Pavilion starting at 3am Tuesday morning. The next eclipse will be in the fall during the early morning hours of October 8th.
If you cannot join us early Tuesday morning, I hope you have a chance to stop by the Planetarium during April. For Spring Family Weekend (April 12th) we will be presenting shows from 1-3pm. Reservations are available when you sign-up online for the weekend events. We will also be presenting shows during Westmoreland County Earth Day on April 27th. Finally, although it has nothing to do with Astronomy, I hope to see you at the Trooper Iwanic 5K or 10K Run on Saturday, April 26th around the Saint Vincent Campus. I am planning on running the 10K – slowly. Have a blessed Easter.