The Way 2024 Reshaped Our Perspective of Cosmic Realms
There are a plethora of mind-blowing things in the cosmos, made even more mesmerizing by scientists' ability to visualize and comprehend the rules and phenomena that govern their existence. Each year, researchers make new discoveries and reassess old data, substantially reshaping our understanding of how Earth, our solar system, galaxy, and, frankly, the entire universe evolved.
From breathtaking images to groundbreaking calculations, from black holes and neutron stars to cosmic clouds and gravitational lenses, here's the top astrophysical discoveries and advancements in 2024.
The most ancient black hole ever found
Picture source: Wikimedia Commons
In January, a crew of researchers stumbled upon a black hole that's approximately 400 million years old after the Big Bang. This ancient behemoth is over 13 billion years old, which means it's almost as old as the universe itself (13.77 billion years old). The time gap between the birth of the universe and the formation of this black hole is shorter than the time span between the present moment and the Cambrian explosion on Earth.
The first detailed portrait of a star outside the Milky Way
Artist depiction of the star. Image source: ESO/L. Calçada
In November, the European Southern Observatory’s Very Large Telescope Interferometer captured an image of a star that's 2,000 times the diameter of the Sun, which is situated a staggering 160,000 light-years away. This red supergiant, located in the Large Magellanic Cloud, is surrounded by a shell of material that scientists believe it's discarding as it moves toward its end: a spectacular supernova explosion.
Jupiter's plasma plumes
Illustration: NASA/JPL
The Voyager missions continue to amaze! In January, scientists published an analysis of 45-year-old data from Voyager 2, revealing plasma jets in Jupiter's magnetosheath. Jupiter's magnetosphere is a massive structure, approximately 15 times the size of the Sun.
Farewell, Ingenuity, Mars' trailblazing helicopter
Image credit: NASA
In January, the Ingenuity helicopter embarked on its 72nd flight on Mars. Sadly, this was its swansong: The helicopter suffered damage to a rotor blade during a tricky landing, bringing an end to its aerial activities on the Red Planet. Ingenuity may have had a short life, but its impact on space exploration can't be underestimated. It was the first automaton to achieve controlled, powered flight on another planet, and it paved the way for future aerial vehicles beyond Earth.
An asteroid liberated
Image: NASA/Erika Blumenfeld & Joseph Aebersold
January was a bustling month for space research! The OSIRIS-REx team finally managed to open a tightly-closed container containing a massive amount of space rock, which had been collected from asteroid Bennu in an audacious mission. The Bennu asteroid sample could shed light on its chemical composition and the history of our solar system for years to come.
Spiral galaxies in abundance!
This research revealed 19 images of face-on spiral galaxies. These images serve as a reminder of the scale and grandeur of cosmic objects, and of our puny existence as Earth orbits the Sun, located in a distant corner of the Milky Way.
New moons discovered
Image: Scott Sheppard
In February, astronomers identified previously unnoticed moons orbiting Uranus and Neptune. These moons were spotted using ground-based telescopes; the smallest of them is just 5 miles (8 kilometers) wide, while the largest is 14 miles (23 km) wide. Their orbits range from 680 days to 27 years. It seems even our neighboring solar system still has lots of secrets to reveal!
A star's supernova giving birth to a black hole
Image source: E. Zimmerman et al., Weizmann Institute of Science/Liverpool Telescope
Supernovae are the spectacular and violent deaths of stars, resulting in the expulsion of material into space and the formation of a black hole (a region of spacetime with gravitational pull so intense that not even light can escape it). In March, astronomers captured images of a star undergoing a supernova explosion, offering a close-up view of this incredible process.
The great North American solar eclipse
Image credit: paramsach (Fair Use)
On April 8, the Moon partially covered the Sun across North America, providing spectators with an awe-inspiring glimpse of our local cosmic environment. At the peak of the eclipse, the Sun appeared as a thin ring of light around the Moon, causing daytime darkness.
A lava lake on a moon
Gif: NASA/JPL-Caltech/SwRI/MSSS
Not all moons are like ours (cheese, of course, notwithstanding). Moons in our solar system vary greatly in shape, size, temperature, and composition. Some moons are believed to harbor subsurface oceans where life might thrive, while others, like Jupiter's Io, are extremely hot. In fact, recent Juno flybys of Io revealed a lava lake on its surface, amazingly captured in a 3D animation.
Jupiter and its moons
Image: NASA/JPL-Caltech/SwRI/MSSSImage processing by Thomas Thomopoulos © CC BY (main image)Image processing by Brian Swift © CC BY (Figure 1)
Updating on Io-Jupiter's moons, they are quite diverse, boasting 95 in total, all deserving recognition. In April, we shared a slideshow featuring Jupiter's moons, including Io and Europa, which will both reappear later in this round-up as captivating spots for planetary science and astrobiology research.
A chaotic solar episode
Image: NASA/SDO
In May, the Sun unexpectedly became frenzied, with solar flares and coronal mass ejections (CMEs) resulting in the Space Weather Prediction Center issuing a severe geomagnetic storm warning, its first since January 2005. This activity led to breathtaking auroras across Earth, even as far south as Florida and Texas. This turbulence signaled further solar storms over the coming months, unforeseen as the Sun approached its solar maximum.
Auroras on Mars
Gif: NASA/JPL-Caltech
The heightened solar activity served as a reminder of our place in the solar system. On Mars, the Curiosity rover recorded evidence of auroras, giving researchers a rare glimpse into these phenomena on other planets. The rover's Radiation Assessment Detector recorded its highest surge in radiation since its arrival on Mars, and NASA suggested that an astronaut standing on Mars's surface would have received radiation equivalent to 30 chest X-rays from the solar outburst.
Webb's farthest galaxy yet
Image: NASA, ESA, CSA, STScI, Brant Robertson (UC Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)
Researchers announced the discovery of the most distant and earliest galaxy yet, appearing less than 300 million years after the Big Bang. This stellar system, hailing from the Cosmic Dawn, showcased the Webb Space Telescope's ability to penetrate interstellar dust and capture images of the universe's faintest and most distant—ergo, earliest—objects. The team concluded that the galaxy's light is primarily generated by large stars, rather than material falling into a supermassive black hole.
The most distant merging quasars yet
Illustration: International Gemini Observatory/NOIRLab/NSF/AURA/M. Garlick
In June, a team of astronomers unveiled the most distant merging quasars—the bright cores of galaxies—ever observed. This merging pair was the first confirmed from the Cosmic Dawn, with each quasar's core black hole weighing about 100 million times that of the Sun. These observations provide researchers with invaluable insight into the early universe's structure and evolution.
A lunar tunnel
The Mare Tranquillitatis pit crater. © NASA/Goddard/Arizona State University
Researchers suggested in July that a pit crater on the Moon might harbor a tunnel. Located in the Moon's Sea of Tranquility, where Apollo 11 landed in 1969, this lunar tunnel could be a valuable asset for future missions to the Moon, offering protection from cosmic rays and solar radiation and providing thermal stability due to the Moon's surface temperature fluctuations.
Outstanding views in astronomy
© Chester Hall-Fernandez
Take some time to explore this year’s finalists for the Astronomy Photographer of the Year competition. Views ranging from the Sun's surface to Iceland's aurora are presented, demonstrating the splendor of the cosmos. Whether observed through space telescopes and distant orbiters or captured with a camera and Earthbound eyes, the universe's beauty is equally awe-inspiring.
Deciphering the 'Wow!' signal
The computer printout on which astronomer Jerry Ehman wrote ‘Wow!’ next to the signal's detection. Credit: Big Ear Radio Observatory
In August, the Arecibo 'Wow!' project presented data suggesting that the mysterious signal detected in 1977—often associated with extraterrestrial life—may have been brought about by a massive hydrogen cloud. This hypothetical magnetar, a highly magnetized neutron star, may have excited atoms in the hydrogen cloud, giving rise to the 'Wow!' signal. While intriguing, this theory steers clear of the extraterrestrial life hypothesis.
Betelgeuse and its companion
A 2020 image of Betelgeuse as seen by the Hubble Space Telescope. Image: ESO/Digitized Sky Survey 2. Acknowledgment: Davide De Martin.
In September, researchers proposed that Betelgeuse's peculiar dimming pattern may be due to the presence of a companion star—dubbed 'BetelBuddy'—orbiting the red supergiant star. Betelgeuse's brightness makes its companion star invisible, but this theory could explain Betelgeuse's fluctuating light, with a supernova event imminent in the not-so-distant future.
Gargantuan black hole jets
An artist's impression of the gigantic black hole jet system stretching through the cosmos. Illustration: E. Wernquist / D. Nelson (IllustrisTNG Collaboration) /M. Oei
Black holes can sometimes eject streams of matter traveling close to the speed of light. These streams are amongst the most intense structures in the universe, and they grew even more extreme in September, when analysts discussed the largest-ever-discovered streams. These streams are part of a mega-structure named Porphyrion, after a giant from Greek mythology. They extend over 140 Milky Ways, and could significantly impact their surroundings in the universe.
Likewise, in September, another group of researchers discovered that black hole streams can cause stars to explode. Research on black hole streams is a field to monitor in 2025, as researchers gain more insights into how these remarkably large and powerful structures induce changes in their surroundings.
A breeding ground for dark matter
A neutron star at the core of the Crab Nebula. Image: ESA/Hubble / Wikimedia Commons
There's still debate on what comprises dark matter, the approximately 27% of matter in the universe that scientists cannot directly observe but interacts gravitationally with normal matter. In October, a team of experts suggested that one dark matter candidate—axions—could form clouds around neutron stars, providing a new opportunity for researchers to focus their searches for dark matter particles. Space telescopes such as the European Space Agency’s Euclid telescope are dedicated to dark matter detection, but the team’s research suggested that a space-based radio telescope would be particularly useful for precisely locating neutron stars.
The Arecibo collapse report
The Arecibo Telescope being demolished in December 2021. Photo: Tedder / Wikimedia Commons
A report released in November by the National Academies of Sciences, Engineering, and Medicine identified the primary cause of the Arecibo Observatory's collapse. The observatory crumbled in December 2020, but the report revealed the true culprit: damage from Hurricane Maria was worsened by the degradation of zinc in the telescope's cable sockets; combined stressors led the cables to fail, causing the observatory's suspended platform to collapse through the telescope's colossal dish.
The Perseverance rover leaves its Martian cradle
A view from the Perseverance rover. Image: NASA/JPL-Caltech
Scientists at NASA's Jet Propulsion Laboratory recently announced that the Perseverance rover had successfully emerged from Jezero Crater, where the rover landed in February 2021. Now, the rover will investigate roughly four-billion-year-old rocks that could provide insights into Mars' formation, as well as Perseverance's search for evidence of ancient microbial life.
The mystery of the universe's expansion deepens
The galaxy cluster Abell 370, a gravitational lens 4 billion light-years away. Image: NASA, ESA, and J. Lotz and the HFF Team (STScI)
Last month, an “Einstein Zig-Zag” in space offered a new chance for astrophysicists to determine the Hubble constant, the number indicating the rate of the universe's expansion. The constant is inconsistent; depending on how you calculate it, you get different results. The Einstein zig-zag—actually a compound gravitational lens—could constrain the constant, by showing how it aligns with the cosmological model.
As we discuss gravitational lensing and the Hubble constant, it's worth mentioning research published in October that described a supernova that appeared three times in the arc of a gravitational lens some 3.6 billion light-years from Earth. Gravitational lenses work as windows into the universe's more distant past, magnifying the details of deep time for our viewing pleasure.
Something cold and wet near Uranus
Miranda, as seen by Voyager 2 in 1986. Image: NASA/Jet Propulsion Laboratory-Caltech
Yes, you read that correctly. In October, a group of experts concluded that Uranus' moon Miranda may possess a liquid water ocean—or had one in the distant past. The findings added another moon to the expanding list of fascinating candidates for astrobiological exploration. Because liquid water is essential for life as we know it, researchers believe that reservoirs of liquid water—including subsurface oceans on moons like Miranda, or Jupiter's Europa—are promising locations to search for life.
A supercomputer's simulation of the universe
A sample of simulations showing a model of the expanding universe (left) and a zoomed-in view of tracer particles (right).Image: Argonne National Laboratory, U.S Dept of Energy
In November, scientists employed the world's most potent supercomputer to simulate the universe's conventional physics, as well as the behaviors and qualities of dark matter. The supercomputer is called Frontier, and can perform a quintillion (one billion-billion) calculations per second.
Frontier's simulations revealed the evolution of the universe as it expanded and how galaxies formed and moved as the universe unfolded. Frontier is no longer the world's fastest computer—it was dethroned by El Capitan in November—but the supercomputer can still contribute to our growing comprehension of the cosmos.
The discovery of the ancient black hole in January highlights the advancements in space technology and science, as researchers were able to detect a black hole that is almost as old as the universe itself. Furthermore, the future of space exploration looks promising as scientists continue to use advanced technology and make groundbreaking discoveries, such as the first detailed portrait of a star outside of our Milky Way in November.
