What’s Ahead in 2025?
by Sam Atkins
With 2024 wrapped up, and now a quarter of the way through the 21st century, it’s time to look forward to what is to come and this year is shaping up to be quite promising. We are seeing the dawn and progression of many ambitious science missions and a lot of fun things happening with the moon and planets!
MAJOR LUNAR STANDSTILL
Image credit: Scott Sutherland (Wikimedia Commons)
Peaking this month, but visible through much of the year, we have reached what is known as a major lunar standstill. This is a rare but regularly occurring configuration between the Earth and Moon that has the latter appearing at its highest and lowest possible points in the sky.
To better understand this phenomenon, we must first understand that the Earth rotates on an axis and that axis is tilted by 23.5°. During the solstices, the Earth’s poles are tilted toward and away from the Sun, which puts it 23.5° above or below the celestial equator. This puts the Sun very high in the sky during summer and very low in the sky during winter. Conversely, during the equinoxes, the Sun is aligned with the celestial equator. In a nutshell, the Earth’s tilt affects how high and low in the sky the Sun goes throughout the year.
The second thing we must understand is that the Moon around the Earth, just like planets around the Sun, orbits on an incline. This means that the Moon’s orbit around Earth is tilted relative to Earth’s orbit around the Sun. The Moon has a somewhat pronounced inclination relative to Earth of about 5°. There is a point in the Moon’s orbit that is highest and a point that is lowest. However, the direction of these two points gradually shifts over time in a cyclical nature. This is known as precession.
Every 9.3 years (twice in an 18.6 year cycle), the orientation of the moon’s orbital incline lines up with the orientation of the Earth’s axial tilt and we get what is called a major lunar standstill. Essentially, a major lunar standstill occurs when the moon reaches the highest point in its inclined orbit at the same time that the Earth’s axial tilt is point directly toward it.
This maximizes the extremes in altitude that the moon reaches in the sky. Also, expect to see the moon rise and set at more northerly locations. Beyond that, there are some other effects as well. We will get higher high tides and lower low tides. Eclipses become less frequent as the moon travels much further from the ecliptic, where the Sun remains. It’s nothing that will significantly affect your life but interesting to see how all these gravitational systems and motion work together in such a complex dance.
PRIVATE COMPANIES JOIN IN ON LUNAR MISSIONS
Image credit: Intuitive Machines
As of the last twenty years, water has been known to exist on the Moon but little is known about its form, abundance or distribution. Learning about this is fundamental to much of the current interest in returning to the Moon. Water can be a valuable resource to sustain a human presence on the Moon. It not only provides hydration for astronauts but hydrogen can be extracted from it to produce rocket fuel.
Early this year, a Falcon 9 rocket is set to launch from the Kennedy Space Center in Florida, carrying two mission payloads to the Moon:
The first payload will be a lunar lander, part of the IM-2 mission being carried out by the private space company, Intuitive Machines. Equipped to the lander is a whole suite of science hardware that will deployed at the Shackleton crater at the lunar south pole. IM-2 is part of NASA’s Commercial Lunar Payload Services, an initiative to hire private companies to establish reliable means of transporting new technologies, such as rovers, from the Earth to the Moon. The objective will be to gather samples of subsurface water ice and demonstrate an ability to extract on site resources for potential long-duration human excursions of the lunar surface. This mission comes nearly a year after Intuitive Machines’ first attempt at putting a lander on the moon ended in failure after the Odysseus spacecraft landed on its side, near the lunar south pole. It was the first piece of American hardware to soft-land on the lunar surface since the final Apollo mission left it in 1972 as well as the first soft lunar landing by a private company. The lander could not sustain longer than a month but with failure comes lessons learned and the history of space exploration is a history of persistence and innovation.
Also aboard the Falcon rocket will be NASA’s Lunar Trailblazer orbiter, a relatively small satellite that will observe water ice deposits across the lunar surface and analyze how its distribution relates to the Moon’s geology. Where does this water originate from? Does water accumulate more at certain latitudes or certain surface makeup? In what ways does the distribution of water change with sunlight? The orbiter will provide data using two instruments: a spectrometer to analyze the wavelength of light that reflects off the lunar surface and a thermal mapper to detail the surface temperature.
A date has still yet been confirmed for launch which puts the predicted January launch into question but I will keep tabs on this mission to keep you in the loop!
Another planned mission to the Moon involves another Texas-based space company called Firefly Aerospace. The “Ghost Riders in the Sky” mission will launch a lunar lander of its own called Blue Ghost 1. This tech is bound for a solitary 150 meter tall, 6.4 km-wide lunar mountain located in Mare Crisium, a particularly distinct region on the Earth-facing side of the Moon. The goal of Blue Ghost 1 is to spend two weeks in lunar daylight to analyze how the solar wind and Earth’s magnetic field interact with the lunar regolith. At the end of the mission, the lander will snap what I expect to be a dramatic shot of the Sun setting on the lunar horizon! All the while, the lander will monitor how this change in daylight affects the surface.
MARS OCCULTATION & OPPOSITION
Image credit: Fifth Star Labs - Sky Guide
On the evening of January 13th, the Moon will occult Mars, meaning it will pass directly in front of the planet in its orbit around Earth. This is possible because Earth and the other planets of solar system follow pretty similar orbital planes around the Sun, though not identical. Earth’s orbital plane is represented in the celestial sphere as a line called the ecliptic. The Sun, Moon and planets never stray far from this line as they appear to travel around it. A consequence of this is that the Moon, which is the closest object and thus the largest appearing object (discounting the blinding Sun), periodically crosses over all the smaller more distant objects. Occultations are not that uncommon but this one in particular is kind of cool because the Moon is occulting Mars just a few days before another cool thing that is happening.
On January 15th, Earth will reach opposition with Mars. This is when our planet passes directly between the Sun and Mars, leaving them on opposite sides. Opposition marks our closest approach with the red planet and makes this time the greatest opportunity to view Mars through a telescope. When the red planet is far from us, even with great magnification, it appears as a disparately small point of light. But from the closest distance and with just a moderately-sized telescope, you’ll not only see the planet’s disk shape but even some surface features like the polar ice caps.
The occultation and opposition of Mars will combine to create a pretty cool viewing opportunity that isn’t quite as common as the two things on their own. Beyond this, we can expect Mars to grace our evening skies for much of the rest of 2025, along with more lunar close encounters!
EUROPA CLIPPER & HERA PASS MARS
Image credit: NASA’s Eyes on the Solar System
The mission to study Jupiter’s icy moon, Europa, launched this last October. The space probe’s objective is to image and analyze the moon to confirm the existence of a subsurface ocean and determine its capacity to harbor life. The implications of this mission has the potential to be profound, which makes the wait to get there that much harder.
Rejoice, nonetheless, that with patience comes eventuality. Kicking off March, the Europa Clipper spacecraft will reach the first milestone in its 6.5 year journey to the Jovian system. The probe will make a very close flyby of Mars which will leverage the red planet’s gravity to give it a speed boost. This is called a gravity assist maneuver and is a clever way we’ve figured out how to cover great distances in the solar system without using a ton of fuel.
The rendezvous with Mars will slingshot Europa Clipper in a wide arc all the way around the Sun where it should eventually end up back at Earth. This solar orbit will take the better part of two years before the probe returns to our home planet in December 2026 for one more gravity assist that will hurl it straight into Jupiter’s path. It may seem like an unnecessary detour but fuel savings will make it worthwhile.
Another spacecraft that launched in October as part of the ESA’s Hera mission will also reach Mars in March to perform a gravity assist. However, this will send the probe directly towards its final destination in the asteroid belt. The Hera mission is a follow up of NASA’s DART mission that intentionally collided a spacecraft with an asteroid in 2022. Hera is there to investigate the aftermath and provide us with valuable data on how best to defend Earth from rogue asteroids.
TOTAL LUNAR ECLIPSE
Image credit: Fifth Star Labs - Sky Guide
We will not be seeing a repeat of last year’s incredible total solar eclipse here in North America any time soon. In fact, Maryland is due to just barely miss the next one passing over the Atlantic Ocean in late March as it will resolve just before the sun rises. If you do want to see any of it, you’ll need to travel to the most northern regions of Maine to get a brief glimpse of the solar crescent. Otherwise, you’ll need to leave the country for Canada, Europe, Russia or North Africa.
For the rest of us who can’t travel for the weekend, we will be granted a different show just two weeks prior. On the night of March 13th going into the morning of March 14th, we will be graced with a total lunar eclipse. It is probably obvious that solar eclipses and lunar eclipses often come paired together as they are both allowed by different configurations of the same alignment between the Sun, Earth and Moon.
The event will be visible from Maryland in its entirety. However, if you want to see it, you’ll need to be willing to stay up really late. The eclipse won’t begin until almost midnight and won’t reach totality until 2:26am, lasting for a little over an hour. The moon will pass out of Earth’s shadow completely by 6:00am, just an hour and a half before setting. Night owls, rejoice! Morning people, godspeed…
SATURN’S RINGS PULL A DISAPPEARING ACT
Image credit: Fifth Star Labs - Sky Guide
Just like Earth, Saturn orbits the Sun on an axial tilt. In fact, it’s somewhat similar to ours at just less than 27° (versus Earth’s 23.5°). We can see this tilt by observing the lateral bands across the planet’s surface as well as the prominent ring system, which are aligned with the planet’s equator. Also like us, Saturn’s orbit around the Sun changes the orientation of its tilt towards the Sun, though Saturn’s orbit is much slower taking 29.5 Earth years to complete one revolution. As the years go by we can see the angle of Saturn’s rings change with the orientation of its tilt, making them appear wider or narrower. Twice throughout a revolution, Saturn’s spring and fall, the rings become angled directly sideways in relation to the Sun and we see them edge-on. Though, by see them, I mean we don’t see them at all.
What many probably don’t realize is just how incredibly thin Saturn’s rings are. They are made up of trillions of pieces of rock and ice orbiting around the planet like heavy traffic lanes full of little moonlets. While they span a gargantuan 282,000 km from end to end, which is almost three-quarters of the distance between the Earth and Moon, they are only about a kilometer at their thickest. In some places they may only be 10 meters. That’s 282 million meters to only 10. To give you a sense of how thin that is, if Saturn’s rings were as thin as a sheet of paper, that sheet of paper would have to stretch 2.74 km (1.7 mi) across. Or rather, if you had a regular width sheet of paper it would have to be 10,000 times thinner to be proportionate to the thinness of the rings.
From late March until early May, Saturn’s rings will be turned away to where they become edge-on to us and, for all intents and purposes, will become invisible. Fear not, as this effect will only be temporary. After about a month or so, Saturn’s orbit will orient the ring plane from us and the Sun again. After this point, and for the next fifteen years or so, Saturn will present the “underside” of its rings as the side closest to us will be tilted upward.
You’ll only get a handful of opportunities in your life, at most, to see this unique view of the ringed wonder so I suggest you take advantage of it. Perhaps a visit to HCAS’s March and April open house will be in order?
SPACEX TO ATTEMPT IN-ORBIT PROPELLANT TRANFER
Image credit: SpaceX
One of the biggest logistical hurdles of space exploration is fuel constraints. Rockets have strict weight limits to ensure they can overcome Earth’s gravity and fuel often accounts for the bulk of it. Once a spacecraft leaves the surface, whatever fuel they have left will have to get them whatever distance they need to go and, believe me, the distances in the solar system can be vast. As humans venture further and further in to it, the problem of fuel is one that must be dealt with.
SpaceX has been experimenting with and testing new technology that would allow their Starships to be refueled while still in space. This is especially relevant as these rockets are to be the ones to bring astronauts to the lunar surface during the upcoming Artemis III mission in mid-2027. Just this last March, during Starship’s third test flight, they transferred liquid oxygen propellant between two tanks inside the rocket. This was meant as a precursor for an upcoming demonstration expected to be performed this year.
Set for a March 2025 window, the refueling demonstration is intended to proceed as follows: A Starship rocket will launch into low-Earth orbit serving as a target vehicle. Its power systems and battery capacity will be augmented to sustain the three to four week wait for the second Starship rocket that will launch as the chaser vehicle (aka the refueling tanker). The chaser will enter into low-Earth orbit to rendezvous with the target where they will autonomously connect belly-to-belly (as shown in the illustration above). They will begin to transfer propellant from the chaser vehicle to the target vehicle using a pressure differential. This demonstration will give engineers a good idea of how many refueling tankers will be required to fill up a Starship heading for the Moon.
FIRST INDIAN TO SPACE SINCE COLD WAR AND FIRST EVER TO ISS
Image credit: Axiom Space
In 1984, Rakesh Sharma launched in a Soviet rocket to rendezvous with the Salyut 7 space station. This was part of the Soviet Union’s Interkosmos program which aimed to assist their allies with both crewed and uncrewed space missions. Sharma became the first Indian citizen to ever fly into space and to this day, he is still the only one as well as the only Indian to recieve the Hero of the Soviet Union distinction. He remains a revered figure in India even today at the age of 75.
For the first time in four decades, another Indian citizen is set to go into space. India’s space program has been making great strides in becoming an active player in the exploration of space. In 2023, they became the fourth nation to successfully land a spacecraft on the Moon. This milestone definitely put some wind underneath their wings as they have since begun to announce ambitious human spaceflight plans. As part of this ambition, Indian Air Force test pilot Shubhanshu Shukla will join the Axiom-4 mission to the International Space Station. This will not only mark the first time an Indian has gone to space since Sharma did during the cold war, but the first time any Indian has ever visited the ISS. Axiom-4 is a joint mission operated by private space companies Axiom Space and SpaceX and coordinated with NASA. Shukla will pilot a SpaceX Crew Dragon spacecraft to the ISS where they will participate in the space stations ongoing science missions. Alongside him, three other astronauts will represent the United States, Poland and Hungary. For the latter two, this mission represents their respective countries’ first government-sponsored flight in over 40 years as well.
The mission will launch no sooner than April 2025 and is expected to last for two weeks.
ESCAPADE ORBITERS TO STUDY MAGNETIC FIELD OF MARS
Image credit: Rocket Lab USA, UC Berkley
This spring, NASA is set to launch the Escape and Plasma Acceleration and Dynamics Explorers (ESCAPADE) mission. The mission will send twin Photon orbiters on a journey to Mars where they will enter into a highly-elliptical. As the mission proceeds, these two satellites named "Blue" and "Gold" — as a nod to the University of Berkeley's school colors where they were designed — will make progressively closer and closer passes of the red planet. The objective of this mission is to gain a better understanding of how Mars lost its atmosphere.
The prevailing hypothesis has been that Mars in the distant past had a much thicker atmosphere and an overwhelming amount of evidence suggests that Mars was covered in rivers, lakes and oceans of liquid water. At some point, the planet’s liquid iron core is thought to have cooled and solidified. Without the churning of this electrically-conductive metal, Mars’ magnetic field would have no longer been able to sustain, and without its magnetic field, the planet’s thick atmosphere would have been left naked to the punishing solar wind from the Sun and been gradually stripped away. With an atmosphere only 1% as thick as Earth’s remaining, the planet has become a dusty and cold world and its oceans have dried up. The only water that we know remains exists at the icy polar caps.
The orbiters are equipped with a series of science instruments like magnetometers which will measure the direction, strength and relative change within what remains of Mars’ magnetic field. They also have electrostatic analyzers which can sample the charged particles flowing through the magnetosphere to analyze their energy and mass. Scientists can use this data to infer the strength and structure of the magnetic field.
Due to the delay, the launch is less ideally timed for Mars’ close approach to Earth in its orbit. Therefore, the ESCAPADE mission must first perform a gravity assist with Venus to slingshot the orbiters to Mars.
TIANWEN-2 TO BRING BACK ASTEROID SAMPLE
Image credit: CNSA
In late spring, China is set to launch a long-duration space mission dubbed Tianwen-2.
The first objective is to rendezvous with Kamo’oalewa, a small near-Earth asteroid that orbits the Sun in sync with us. It is estimated between 40 and 100 meters wide and is believed to have originated from the moon before a meteor impact blasted it into space. It is one of five known quasi-moons but believed to be the most stable in its co-orbit. There has been much interest in this object since its discovery in 2016, with Tianwen-2 as one of the latest missions proposed to study it. China wants to send a car-sized probe out to the asteroid, land on it, extract regolith samples and then return them to Earth. This will be the first attempt by a spacecraft to use what’s called an anchor-and-attach method of sample extraction from an asteroid. Once the sample is obtained, Tianwen-2 will return to Earth where the sample will be dropped down to the surface via a capsule.
The probe will not return to Earth itself but instead use our planet to perform a gravity assist to take it to its second objective, a comet designated 311P/PANSTARRS. This objective will be purely to study the object rather than bring back a piece of it. In fact, Tianwen-2 will be fitted with a plethora of science instruments to study both objectives, ten to be exact, mostly to do spectrographic work. This involves analyzing wavelengths of light from the objects that will reveal details about their composition.
Mind you, this second objective is years away, not expected to arrive until the mid-2030’s, hence it being a long-duration mission. However, the first sample return objective should only take a few years.
SATURN & NEPTUNE CONJUNCTION
Image credit: Fifth Star Labs - Sky Guide
Conjunctions happen all the time, but conjunctions between two planets of the outer solar system are few and far between due to the sluggish nature of their distant orbits. For this reason, it is worth mentioning that Saturn and Neptune will come within a single degree of each other early this summer. Due to Neptune being so far away (4.4 billion km at its closest to Earth), it will not be visible with the naked eye so only those with a moderately-sized telescope will be able to appreciate this celestial encounter. This will be the first in a pair of conjunctions as Saturn will soon enter into a retrograde orbit away from Neptune before returning to it again in February 2026. After that? It will be another 35 years before the next one. Take advantage if you can.
JUNO’S DEATH DIVE
Image credit: NASA, JPL-Caltech
The mission of the Juno spacecraft, which has been orbiting Jupiter since 2016, is finally coming to a close. It had initially completed its planned mission after two years of orbiting and gathering data on the atmosphere, magnetic field and internal structure of the gas giant. The findings were so significant that the mission was extended, twice. First, to 2021, and then again to 2025. Along the way, Juno captured the most vividly beautiful images of Jupiter in human history.
However, the mission cannot be extended in perpetuity. The probe’s fuel is finite and Juno’s close flybys of the Jovian atmosphere gradually decay its orbit. NASA must also consider the allocation of resources to new science missions. Thus, it has been decided that at the end of this summer, Juno will be intentionally deorbited which will send the spacecraft careening into the tempests of the gas giant’s stormy atmosphere and be completely destroyed. This ‘death dive’ is in line with longstanding protocols which attempt to protect other solar system bodies from contamination. Were Juno to be left in orbit, there is a chance it could end up colliding with the surface of one Galilean moons and potentially contaminating them with foreign materials or microbes from Earth, especially since we don’t know if these world may harbor life of their own. Any future missions to Jupiter certainly don’t need a giant piece of metal needlessly hurling around the same space at 112,000 km/h.
As sad as it is to see such an iconic mission coming to an end, I am personally excited to the inevitable final photos we get as the probe dives down to Jupiter’s cloud tops, much like we saw when Cassini did the same at Saturn. You can also be sure that I will be, at some point soon, doing a full retrospective of the Juno mission’s journey and detail what it is that we learned about Jupiter and its moons. On the bright side, science doesn’t stop as long as there is a hunger for more and we will see another mission to Jupiter as Europa Clipper is already on its way.
While 2025 was supposed to bring us a manned flyby of the Moon, this year is still set to bring its fair share of science and spectacle. I’ll remind you as we come closer to each of these and give you a deeper rundown of what’s going on. If anything changes, I’ll be sure to update you when I can. I’m excited for another great year and hope you all are looking forward to it as well! See you around!