Looking Back at 2024
by Sam Atkins
2024 is at an end and it did not disappoint in the world of astronomy. Records were broken, exciting new science missions were launched, and we were treated to a variety of unique phenomena in our skies, both during the day and night. Here are some of the more notable things that took place over the last year.
JAMES WEBB FINDS FURTHEST GALAXY EVER
Image credit: NASA, ESA, CSA, STSci, Brant Robertson (US Santa Cruz), Ben Johnson (CfA), Sandro Tacchella (Cambridge), Phill Cargile (CfA)
The James Webb Space Telescope started off the year with a bang, discovering the galaxy JADES-GS-z14-0 (seen in the pullout panel above). It is located a staggering 13.5 billion light years away in the Fornax constellation and is currently the most distant galaxy and astronomical object that we have ever identified.
This distance was determined by using JWST’s near-infrared spectrograph to analyze the emission lines of the galaxy’s spectra. Astronomers look for something called a “redshift” in which the wavelengths of light we receive from an object appear longer (and therefore redder) than they are supposed to. This indicates that the wavelengths are being stretched out via the Doppler effect as the object is moving away from us. The stronger the redshift, the faster away from us the object is moving.
According to Hubble’s law, the distance of an astronomical object is proportionate to its redshift (aka the speed in which it is receding from us). This means that the further away an object is the faster away from us it is moving and vice versa. The redshift of far away galaxies is one of the primary pieces of evidence that the universe is expanding.
Based off its redshift, JADES-GS-z14-0 is believed to have formed only 300 million years after Big Bang. This is when the Universe was just 2% of its current age!
THE GREAT NORTH AMERICAN ECLIPSE OF 2024
On April 8, 2024, there was a total solar eclipse visible from the United States. This is when the moon crossed between the Sun and Earth, casting its huge shadow directly onto our planet’s surface. The path of totality crossed through numerous major cities such as Dallas, Little Rock, Indianapolis, Cleveland and Buffalo. However, there was plenty a sight to see from around the country, even here in Maryland where the moon covered nearly 90% of the Sun. Many people in Harford County joined HCAS members at the Joppa branch of the Harford County Public Library to watch the action unfold! Others braved traffic to catch the eclipse from totality, including HCAS’s Brent Mantooth who captured award-winning images of the event (shown below)! Where were you when it happened?
This image of the total solar eclipse was captured by HCAS’s Brent Mantooth and won him first prize for photography at the 2024 Bel Air Arts Festival! Image credit: Brent Mantooth - Curious Cat Arts
You can learn about Brent Mantooth’s participation in Harford County’s art festivals here: Exhibition at Bel Air Arts Festival — Harford County Astronomical Society, Inc.
You can see more of Brent Mantooth’s astrophotography work here: ArtCatalog
Alas, we’ll have to be very patient as it was the last total solar eclipse that will be visible from the United States until 2044. If you can’t wait that long, you’ll have to do some travelling.
MOST MASSIVE STELLAR BLACK HOLE DISCOVERED
Image credit: ESO, M. Kornmesser
On April 16, 2024, the ESA’s Gaia space telescope identified a stellar-mass black hole located 2,000 light years from Earth.
Stellar-mass black holes are the dead remnants of gargantuan stars that collapse and explode into a supernova. The remaining core becomes so dense and its gravity so strong that nothing that enters its event horizon, not even light, can escape.
When Gaia was observing an old giant star in the Aquila constellation, scientists noticed a peculiar wobble in its movement which suggests it is locked in an orbit. Based on the specific measurements of this orbit, astronomers at the European Southern Observatory have confirmed that the star is orbiting a black hole and confirmed its mass. Designated Gaia BH3, this black hole is estimated to be 33 times more massive than our Sun, making it the most massive of all the stellar-mass black holes found within the Milky Way.
To be clear, stellar-mass black holes are a distinct class of black holes born from a dying star. BH3 is not the most massive black hole in the galaxy, as that title belongs to the supermassive black hole at the center of the Milky Way, Sagittarius A* which is 4 million times the mass of our Sun. However, BH3 is incredibly and uniquely hefty for a stellar-mass black hole.
At only a few thousand light years from Earth, it is also the second closest black hole that we are now aware of. It is beat only by Gaia BH1 which was discovered by Gaia only a few years ago.
FASTEST SPINNING NEUTRON STAR DISCOVERED AND THAT’S NOT EVEN THE COOLEST PART
Image credit: ESA
As explained in the previous entry, when high-mass stars collapse and die, the highest mass stars become black holes. For those stars that are not quite massive enough to become black holes instead become neutron stars. Don’t be fooled. Neutron stars are some of the most extreme objects in the known universe. An object heavier than the Sun crushed down to the size of New York City, just a single teaspoon of its material would weigh more than Mount Everest.
NASA has a special X-ray telescope attached to the International Space Station called NICER (Neutron Star Interior Composition Explorer). X-rays are a form of invisible electromagnetic radiation that are more energetic than ultraviolet. NICER’s X-ray Timing instrument (XTI) is made up of a grid of 56 X-ray photon detectors. These are made to record and analyze the intensity of X-ray emissions and their intervals which helps us determine the size and rotation speed of the object that emits them.
Earlier this year, NICER discovered 4U 1820-30, a binary system in the globular cluster NGC 6624 very close to the heart of our Milky Way galaxy. It consists of a neutron star and white dwarf, the latter of which is what remains after a low mass star like our Sun dies. The neutron star is spinning at an incredible 716 times a second. That’s almost 1 rotation per millisecond. You couldn’t blink that fast. It is only rivaled by one other neutron star as the joint fastest-spinning celestial object ever seen.
Want to know something even cooler? With the neutron star being the denser of the two objects, the white dwarf companion orbits tightly around it at a blistering 11 minute interval. That’s the length of the white dwarf’s entire year. This binary system has the shortest orbital period ever seen.
If that’s not cool enough, get ready for this. Because the gravity of a neutron star is so extreme and the white dwarf orbits so close, the neutron star is constantly siphoning gas off its white dwarf companion like a vampire. This matter piles up on the surface until it reaches critical mass and triggers a thermonuclear explosion 100,000 times more luminous than the Sun. As this explosion happens, the neutron star is spinning very fast, and the brightness oscillates. Astronomers were able to determine the neutron star’s incredible rotation speed by counting the oscillations.
BOEING STARLINER MALFUNCTION LEAVES CREW ON EXTENDED ISS MISSION
Image credit: AFP, NASA
This is an ongoing drama that you might remember starting back in the summer. In early June, two veteran astronauts (Barry Wilmore and Sunita Williams pictured above) were tasked with testing out the Boeing Starliner Calypso, the third iteration of an experimental new spacecraft designed to transport astronauts to and from the International Space Station. The spacecraft had issues with helium leaks in its thrusters through uncrewed test flights in the past. However, after making adjustments, it was determined that the issue was within acceptable ranges, posed no safety threat and a crew mission was greenlit.
After many delays, the third test flight (and first crewed test flight) was launched from Cape Canaveral, Florida atop an Atlas V rocket. They were meant to dock with the ISS for eight days and then return to Earth. As the spacecraft entered orbit and approached the ISS, 5 of its 28 thrusters again experienced helium leak issues. However, it was still able to dock with the ISS safely. The spacecraft would remain so that the Boeing crew could spend time trying to diagnose the problem with the thrusters. Alas, they were not able to work out what the problem was and NASA decided it was too risky to send them back. Instead, the Starliner returned to Earth unmanned so NASA and Boeing could gather more data from the homeward flight. It landed in the White Sands Space Harbor, New Mexico in early September.
Meanwhile, the Boeing crew remain onboard the ISS to assist with hands-on science experiments until SpaceX’s scheduled Dragon spacecraft arrives to collect them and their own Crew-9 also onboard. To be clear, they have not been ‘stranded’ as many of the more sensational claims have been made. Many spacecrafts have visited the ISS since. The astronauts have simply remained there in service to a different mission. That’s what they became astronauts for. They are expected to finally return to Earth by March 2025, nine months after they left.
HERA MISSION TO INVESTIGATE SPACE COLLISION
Image credit: ESA
ESA’s Hera mission launched on October 3rd. It is a follow-up mission to NASA’s 2022 DART mission, which intentionally crashed a spacecraft into an asteroid in an effort to test a means of planetary defense against threats from space. Hera is on a journey to visit that same asteroid to investigate the aftermath. How did the impact affect the asteroids orbit? How did it affect the asteroid’s shape and structure? What debris field was created by the impact? This will be an important step in ensuring we don’t follow the fate of the dinosaurs! Hera will arrive in the Didymos binary asteroid system in December 2026. You can read more in my article on the HCAS website: ESA’s Hera Mission (Updated) — Harford County Astronomical Society, Inc.
AURORA IN MARYLAND!!!
Image credit: Gabrielle Wieczorek
We were treated to an unexpected light show on October 10th following a geomagnetic storm which extended the aurorae borealis down through Maryland and beyond.
Geomagnetic storms are generated when intense solar activity interacts with the Earth’s magnetic field. The solar wind essentially rides the magnetic field down to the poles like a surfer riding a wave until the charged particles collide with Earth’s atmosphere. This excites the electrons of the atmosphere’s atoms, and they glow! This is similar to how neon lights work. This luminescence can come in a variety of different colors, most commonly green and red, but sometimes pink, blue, purple or even yellow! The beautiful colors we see in the aurorae come from which elements of the atoms being excited at various altitudes. For example, green and red are often associated with oxygen atoms, with red being more common during intense solar activity.
Many skywatchers around Harford County experienced this aurora firsthand, capturing incredible images of the colorful luminescence dancing around the night sky. You can read about HCAS’s Tim Phelan’s experience here: First Time Seeing the Aurora — Harford County Astronomical Society, Inc.
NAKED EYE COMET!!
Image credit: Sam Atkins
October wasn’t done yet! Soon after the aurorae faded, we were met with another astronomical phenomenon to marvel at. Gracing our twilight skies was Comet C/2023 A3 (Tsuchinshan-ATLAS) which had visited us all the way from beyond the Kuiper Belt, in the furthest reaches of the solar system.
The comet crossed through our inner solar system and rounded the Sun. As the comet began its long journey back to the outer solar system, it passed within 71 million km of Earth on October 12 with its dust tail still burning long and bright. For the better part of a week, this object was easily visible with the naked eye after sunset. By October 15, its naked eye visibility diminished quickly but it was still visible through a telescope for weeks after. As of the time of this post, the comet would be located 408 million km away from Earth in the Aquila constellation. It was the brightest comet in our sky in the last 27 years (for those who remember the incredible Hale-Bopp comet in 1997) and won’t return to our skies for another 80,000 years!
EUROPA CLIPPER TO SEARCH FOR SIGNS OF OCEAN LIFE
Image credit: NASA
NASA’s Europa Clipper mission launched on October 14 following a delay due to Hurricane Milton battering the Florida coast. Europa Clipper will take a journey out to the Jovian system to study, you guessed it, Europa. For those who don’t know, Europa is highly suspected of having a subsurface ocean beneath its icy crust. This is evidenced by stress fractures called lineae across the surface, the detection of saltwater plumes and the disruption of Jupiter’s magnetic field in the space around the moon (a possible consequence of electrically conductive salt water). The Europa Clipper will perform almost 50 flybys of the icy moon to learn everything it can about its geology, atmosphere and any indicators that it could harbor life. Europa Clipper is expected to enter into orbit around Jupiter in April 2030. You can read more in my article on the HCAS website: The Europa Clipper Mission (Updated) — Harford County Astronomical Society, Inc.
SPACEX CAUGHT A ROCKET!
Image credit: Stephen Clark, Ars Technica
2024 was a pretty wild year for SpaceX. They launched 130 rockets which made up half of the launches across the globe, Starlink’s high speed internet subscriber base has doubled, and its wealthy and eccentric founder, Elon Musk, has secured close ties with the incoming presidential administration. SpaceX has become more and more integral to the United States’ adventures in space.
Most recently, the company brought about another spectacle. In the early Texas morning of October 13th, SpaceX carried out the fifth flight test of its crown jewel and the largest rocket ever built, Starship. This was to be a particularly special test. The two-stage super heavy rocket ignited and hurdled into the clouds. Upon reaching an altitude of 70 km, the upper stage separated. It was to reach a sub-orbital trajectory that would end with it crashing into the Indian Ocean. This was successful but the real star of the show was the other half of the rocket.
The Super Heavy booster turned around and fired its Raptor engines, sending it careening back toward the Earth. Back on the ground, the launch tower named “Mechazilla” deployed two large arms called “chopsticks.” As it emerged from the clouds, large flickering flames bellowed out from the below the rocket booster like dragon’s fire. It slowed as it closed the gap with the Earth until it reached Mechazilla. As the rocket slid between the arms, they closed in and grasped the rocket.
The ability to launch a rocket and then land it safely back on the ground is instrumental to making the endeavor of going into space cheaper and faster. Think about it. You don’t have to send the rocket hurdling into the ocean, polluting it. You don’t have to spend all that money to build and transport a new one. The time and money you save can instead be spent getting another rocket back into space quicker. This historic flight test was a huge milestone in making that innovation commonplace.
SUN REACHES SOLAR MAXIMUM
Image credit: NASA, SDO
On October 15, 2024, the Sun was officially announced to have entered its solar maximum period. This is the point in its natural 11-year cycle called the sunspot cycle that the Sun exhibits the most solar activity. This state is determined by scientists at NASA and NOAA who regularly scour the Sun’s surface for sunspots, dark patches that form where convection is inhibited and cools the region. These surface features are reliable indicators of the Sun’s activity level as they are often accompanied by an increase in solar flares and coronal mass ejections. These phenomena can have direct implications on Earth by triggering geomagnetic storms that cause power grid outages, satellite disruption and the amplification of aurorae. With the Sun at solar maximum, expect these to be more common over the next year or so.
This cycle is largely driven by the Sun’s magnetic field, an invisible region of energy that is generated by the convection of electrically-conductive plasma as well as the differential rotation of the Sun itself. Across this 11-year period, the magnetic field becomes more stretched, twisted and tangled until eventually the Sun’s magnetic north and south poles are flipped around. You can read more in my article on the HCAS website: The Sun’s Magnetic Field and the Solar Cycle — Harford County Astronomical Society, Inc.
We expect this solar activity to continue into 2025.
PARKER SOLAR PROBE’S DIVE BREAKS SPEED RECORD
Image credit: NASA
On Christmas Eve, the Parker Solar Probe made history by becoming the fastest object ever built in human history. Again. Shattering its previous record, NASA’s probe dove towards the Sun in its elliptical orbit and got within 3.8 million miles of the solar surface. To maintain this distance against the Sun’s immense gravity, the Parker Solar Probe reached a face-melting speed of 690,000 kilometers per hour (430,000 mph). To put this into perspective, that is fast enough to travel the entire width of the Earth in just over a minute. Yeah.
Along the way, the probe passed through the Sun’s upper atmosphere, called the corona, where it gathered data from passing high-energy solar particles. Scientists will be able to analyze the data and uncover the corona’s many mysteries. Why is the corona so much hotter than the Sun’s surface? How is it able to accelerate the solar wind? Answering these questions will allow us to not only learn more about how stars work but allow us to better forecast solar weather which can be potentially hazardous to our infrastructure on and around Earth. You can read more in my article on the HCAS website: The Parker Solar Probe’s Ultimate Maneuver (Updated) — Harford County Astronomical Society, Inc.
As we leave 2024 behind, let’s be grateful for all the awe and wonder we got to experience and let’s get excited for what’s to come! 2025 is shaping up to be quite a year as well so tomorrow we will take a look ahead!