Tag Archives: galaxy

The Milky Way is like ripples in a pond

Milky Way ripples

The uncertainty of science: New survey data of the stars in the Milky Way suggest that the galaxy is not only corrugated with concentric ripples — like you’d see if you dropped a stone in a pond — it is also about 50% larger than previous estimates.

I have watched the size of the Milky Way fluctuate up and down depending on the research for the past forty years. Sometimes it is larger than expected. Sometimes smaller. Without doubt we are getting a better idea of its actual size, but don’t be surprised if the numbers continue to bounce about for decades, even centuries, to come.

The confirmation that the spiral arms are the equivalent of ripples in a pond is also not surprising, as it confirms the intuitive conclusion of anyone who looks at a whirlpool-shaped spiral galaxy: It is a whirlpool spiraling into the gravity well at its center.

Metals in the inner galaxy

A preprint paper, published today on the astro-ph website but also accepted for publication in the journal Astronomy & Astrophysics, has confirmed what scientists have suspected about the dust and gas between the stars: As you travel closer to the center of the Milky Way galaxy this interstellar medium gets increasingly enriched with heavy elements. The scientists believe this is because the higher rate of supernovae in the inner galaxy sprays space with more of these atoms.

Since the field of extrasolar planets has also found that the more heavy elements a star contains, the more chance it will have planets, the new results above suggest that we will find more planets as we look inward towards the galactic center.