April 2013: Skyfire — The impending birth of our supergalaxy

This month’s issue of Astronomy magazine describes a collision in our galaxy’s future, profiles a historical underdog astronomer, explains how cosmic strings could rule the universe, reviews Celestron’s Nightscape CCD camera, and more.
By | Published: February 25, 2013 | Last updated on May 18, 2023

WAUKESHA, Wis. — Though it will not happen for another 4 billion years, the collision between the Milky Way and Andromeda galaxies will change both the night sky and future astronomers’ studies forever.

After blocking out background galaxies, stretching each other beyond recognition, and undergoing violent bouts of star formation, the two spiral galaxies will eventually combine into one giant elliptical that science writer Ray Villard calls the “Milky Splay.”

In “Skyfire: The impending birth of our supergalaxy,” Villard describes how the night sky will change in the distant future and how that will affect what scientists can learn about our universe. As he says, “As glacial as the galaxy collision will be, it will change radically what far-future astronomers — human and alien alike — will see in the sky.”

To learn about a galactic collision’s effects on future science, pick up the April issue of Astronomy, on newsstands March 5.

“What string theory tells us about the universe”
String theory — the idea that all particles are fundamentally made of strings vibrating in a 10-dimensional universe — could unify the physics of the large and the physics of the small into a coherent theory of everything. But do strings really rule the universe? And even if they do, can scientists find the evidence necessary to prove it? In “What string theory tells us about the universe,” astronomer Sten Odenwald provides a rundown on the theory, an explanation of the evidence, and some predictions for the future of the strange physics that could underlie our universe.

“The reluctant astronomer”
William Herschel, most famous for discovering Uranus, had a son who created two astronomical catalogs with thousands of objects each, though he is much less well-known than his father. His collection of 5,075 double stars and his 2,300-object list of nebulae and star clusters were invaluable to astronomers of his day and long after. In “The reluctant astronomer,” Andy Burns and Nick Howes profile a man whose influence on astronomy was significant and whose scientific contributions were not limited to a single field.

April sky events visible without optical aid

  • April 14 — The Moon passes 2° south of Jupiter, 2 p.m. EDT.
  • April 22 — The Lyrid meteor shower peaks.
  • April 25 — Full Moon occurs at 3:57 p.m. EDT; partial lunar eclipse.
  • April 28 — Saturn is at opposition.

Also in the April 2013 Astronomy