ShoutingInDigital

The Milky Way is Bigger than First Believed

Posted by James | Filed under news

Astronomers once believed that the Milky Way was but a weaker and lesser sibling to its bigger brother, the Andromeda galaxy. Thought to be smaller in both size and mass, scientists have revealed that this is not the case and that the Milky Way actually measures up comparatively with its neighbouring galaxy.

The study by Mark J. Reid of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, unwrapped the findings at the American Astronomical Society’s convention in Long Beach, California, and gave scientists something to chew on by consigning a decades-long belief to the dustbin.

Using the Very Long Baseline Array (VLBA), Reid’s team multi-dimensionally mapped the Milky Way and found that not only was the galaxy actually 15 percent larger than was first thought, it was also spinning faster than previously believed; as velocity and mass are intrinsically linked, the boosted speed of the Milky Way was estimated to be around 15 percent more than before. This increase in speed helps explain the discovery of a 50 percent increase in mass over previous calculations.

Not wishing to fudge the issue, Reid claimed that the original estimates of the solar system’s speed were based on one-dimensional velocities, which were obtained solely from Doppler shifts. Due to the research team’s 3D mapping, however, it was possible to gain a more exact measurement. The VLBA is a collection of 10 telescopes situated across North America which when used together provide a higher level of accuracy than was possible before and by using the Milky Way’s stars, the research team were able to use the VLBA to note the location and dimension of time in their cosmic map.

“Previously we thought Andromeda was dominant, and that we were the little sister of Andromeda,” Reid said, “But now it’s more like we are fraternal twins.”

A larger Milky Way also means that the gravity between it and the Andromeda galaxy is much stronger than previously thought; heightening the probability they could crash into one another – probably around 3 billion years from now.

Tags: quirky