Travel the universe with Dr. Ethan Siegel as he answers the biggest questions of all
From newborn planets to entire galaxies, we’re seeing the Universe as never before.
The idea of a modern telescope is simple: collect light from a distant object, at high resolution, and record it.
The Arecibo radio telescope as viewed from above. The 1000 foot (305 m) diameter was the largest single-dish telescope from 1963 until 2016. Arecibo helped pinpoint the location of the first known repeating FRB source. But an array of smaller telescopes can accomplish things that even a massive dish like this cannot. (H. SCHWEIKER/WIYN AND NOAO/AURA/NSF)
But with an array of telescopes, you can do even better.
A large number of dishes close together, as part of ALMA, helps create many of the most detailed images in the fainter areas, while a smaller number of more distant dishes helps hone in on details in the brightest locations. (ALMA / TETSUO HASEGAWA)
Instead of the number of wavelengths fitting across a single dish, your resolution is determined by the distance between dishes.
The Atacama Large Millimeter submillimeter Array (ALMA) are some of the most powerful radio telescopes on Earth. These telescopes can measure long-wavelength signatures of atoms, molecules, and ions that are inaccessible to shorter-wavelength telescopes like Hubble, but can also measure details of protoplanetary systems and, potentially, even alien signals that even infrared telescopes can’t see. (ESO/C. MALIN)
ALMA, the Atacama Large Millimeter/submillimeter Array, consists of 66 large radio telescopes networked together.
Different instruments can reveal different details about any astronomical object, dependent on wavelength and resolution. ALMA, owing to its uniquely high-resolution capabilities, can see details of new star formation and very cool gas better than any other observatory. (ESO, NASA, ALMA, CXC, VLA AND MORE)
Combined, they measure this long-wavelength light to reveal astronomical details as never before.
Optical telescopes like Hubble are extraordinary at revealing optical light, but the expansion of the Universe redshifts much of the light from distant galaxies out of Hubble’s view. Infrared and longer wavelength observatories, like ALMA, can pick up the distant objects that are too redshifted for Hubble to see. (ALMA / HUBBLE / NRAO / NSF / AUI)
Ultra-distant galaxies are better seen with ALMA than even Hubble.
Looking back through cosmic time in the Hubble Ultra Deep Field, ALMA traced the presence of carbon monoxide gas. This enabled astronomers to create a 3-D image of the star-forming potential of the cosmos. Gas-rich galaxies are shown in orange. (R. DECARLI (MPIA); ALMA (ESO/NAOJ/NRAO))
Molecular gas signatures are revealed.
Hubble data (background) and ALMA data (inset, false-colored) have revealed the internal motions, for the first time, of normal galaxies that are so far away. The red and blue portions show the relative redshifts and blueshifts caused by galactic rotation. (HUBBLE (NASA/ESA), ALMA (ESO/NAOJ/NRAO), P. OESCH (U. GENEVA) AND R. SMIT (U. CAMBRIDGE))
Even their internal rotations can be measured.
Observations using the Atacama Large Millimeter/submillimeter Array (ALMA) have revealed an unexpected spiral structure in the material around the old star R Sculptoris. This feature has never been seen before and is probably caused by a hidden companion star orbiting the star. (ALMA (ESO/NAOJ/NRAO)/M. MAERCKER ET AL.)
Dying stars in our own galaxy create remarkably intricate patterns in the surrounding gas.
This view shows a new picture of the dust ring around the bright star Fomalhaut from the Atacama Large Millimeter/submillimeter Array (ALMA). The orange ALMA observations provide information about the size and mass of any orbiting planets present. (ALMA (ESO/NAOJ/NRAO). VISIBLE LIGHT IMAGE: THE NASA/ESA HUBBLE SPACE TELESCOPE)
Young, nearby stars, like Fomalhaut, emit radio light via the protoplanetary disk surrounding it.
A new star, very massive and in the earliest stages of its life cycle, displays a protoplanetary disk and bipolar jets that only ALMA has the capability of revealing. (ALMA (ESO/NAOJ/NRAO))
ALMA captures the birth cries of individual stars.
Multiwavelength composite of interacting galaxies NGC 4038/4039, the Antennae, showing their namesake tidal tails in radio (blues), past and recent starbirths in optical (whites and pinks), and a selection of current star-forming regions in mm/submm (orange and yellows). Inset: ALMA’s first mm/submm test views, in Bands 3 (orange), 6 (amber), & 7 (yellow), showing detail surpassing all other views in these wavelengths. ((NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO); HST (NASA, ESA, AND B. WHITMORE (STSCI)); J. HIBBARD, (NRAO/AUI/NSF); NOAO/AURA/NSF)
ALMA showcases the trails of gas that cool and contract to form new stars during galaxy collisions.
Sugar molecules in the gas surrounding a young, Sun-like star. The combined data from many observatories, including ALMA, reveal these molecular signatures and their locations. (ALMA (ESO/NAOJ/NRAO)/L. CALÇADA (ESO) & NASA/JPL-CALTECH/WISE TEAM)
But most impressively, ALMA reveals unprecedented views of planetary formation around new stars.
Misaligned protoplanetary disks do exist, but we have yet to find a real-life system where protoplanetary disks are actively interacting with one another. This image is based on ALMA data of HK Tau shown in a composite image with Hubble infrared and optical data.(B. SAXTON (NRAO/AUI/NSF); K. STAPELFELDT ET AL. (NASA/ESA HUBBLE))
It maps out the locations of newly-forming planets via gaps in their protoplanetary disks.
The protoplanetary disk around the young star, HL Tauri, as photographed by ALMA. The gaps in the disk indicate the presence of new planets. Once enough heavy elements are present, some of these planets can be rocky. This system is already hundreds of millions of years old, and the planets there are likely nearing their final stages and orbits. (ALMA (ESO/NAOJ/NRAO))
ALMA’s lessons provide educational insights into how our own Solar System formed.
The protoplanetary disk around the star TW Hydrae shows gaps in it, which are inferred to evidence of newly formed/forming protoplanets. Potential planet locations annotated by E. Siegel. (S. ANDREWS (HARVARD-SMITHSONIAN CFA); B. SAXTON (NRAO/AUI/NSF); ALMA (ESO/NAOJ/NRAO))
Mostly Mute Monday tells the astronomical story of an image, phenomenon, or observatory in visuals and no more than 200 words. Talk less; smile more.
