Even a century after Edward Hubble confirmed its existence, astronomers learn new details about the Andromeda galaxy that help us better understand our cosmic neighborhood and the wider universe. Earlier this week, NASA released its latest detailed images of the Milky Wayâs spiral sibling, as well an ethereal sonification of its energy wavelengths.
Attaining an outside view of the Milky Way galaxy is a bit like trying to examine the entire planet from your backyardâthat is to say, itâs impossible from humanityâs current vantage point. The next best option for astronomers is gazing at similar nearby spiral galaxies, the closest of which is Messier 31. Also known as Andromeda, the Milky Wayâs most immediate neighbor is about 2.5 million light-years away, and provides an excellent option for studying how spiral galaxies form and evolve over time. Itâs also where a team led by astronomer Vera Rubin first detected the anomalous material now known as âdark matterâ in the 1960s.
The newest glimpses at Andromeda are based on composite data collected by an international array of the worldâs most powerful telescopes, including the Chandra X-ray Observatory, the ESAâs XMM-Newton, and even optical information from a pair of astrophotographers. The various kinds of light span the visible, infrared, radio, and ultraviolet wavelengths. When layered, they depict a vibrant and active galaxy reminiscent of our ownâand the information is already helping experts expand on Andromedaâs ongoing life story.
âFor example, Chandraâs X-rays reveal the high-energy radiation around the supermassive black hole at the center of M31 as well as many other smaller compact and dense objects strewn across the galaxy,â NASA explained in its announcement.
Astronomers arenât limited to studying visual representations of Andromedaâs energy; they can also assess them through sound. In addition to the images, NASA researchers compiled the galaxy datasets into a sonification by separating out each wavelength, rotating them, and stacking them on top of one another in order of their frequency. From top to bottom, that means X-rays, ultraviolet, optical, infrared, and finally radio waves. These are next assigned a range of corresponding notes, with brightness designating volume while spectrum location determines pitch. The result is a dreamlink chorus of tones as the space telescopes traverse Andromedaâs 152,000 light-year diameter.
Thereâs still an untold wealth of information to learn from the Milky Wayâs neighbor, possibly even the means to finally understand the dark matter first detected by Rubin. Thatâs at least what NASA hopes to achieve with the upcoming Nancy Grace Roman Space Telescope currently scheduled to go into operation in 2027.
