Connect with us



A new era of exploration at Jupiter’s moons began last week with the launch of the European Space Agency’s Juice, the Jupiter Icy Moons Explorer. This mission will visit three of Jupiter’s largest moons — Europa, Callisto and Ganymede — to investigate whether they could be potentially habitable, a question that’s been highly debated since the first evidence of subsurface oceans on these moons was seen by the Galileo mission in the 1990s.

The spacecraft launched onboard an Ariane 5 rocket from the European Spaceport in French Guiana on April 14th, 2023. After about 2 hours into the flight, ESA operations confirmed that it unfurled its gigantic 27-meter-(88 ft.) long solar arrays, meaning the launch was successful. Now comes the long flight to Jupiter. Juice will arrive at the planet in 2031, where after the flybys of Europa, and Callisto, the spacecraft will eventually settle into a final orbit around Ganymede.

“ESA, with its international partners, is on its way to Jupiter,” says ESA Director General Josef Aschbacher, in a press release. “Juice’s spectacular launch carries with it the vision and ambition of those who conceived the mission decades ago, the skill and passion of everyone who has built this incredible machine, the drive of our flight operations team, and the curiosity of the global science community. Together, we will keep pushing the boundaries of science and exploration in order to answer humankind’s biggest questions.”

The volume of subsurface water held by Europa, Ganymede and Callisto is far greater than in Earth’s oceans. Juice’s suite of science instruments will provide unprecedented, close-up details to help uncover the mysteries of these enticing moons.

We’ve got our first space #selfie images back from #ESAJuice from the two monitoring cameras! ?

1? Leaving Earth
2? Goodbye, goodbye
3? Solar array deployed
4? RIME antenna (stowed)

More details for each image ?

3? as gif ?

— ESA’s Juice mission (@ESA_JUICE) April 15, 2023

The timing for Juice’s launch was very precise. The launch window was about one second so that the orbital mechanics could allow for the spacecraft’s complex trajectory. The eight-year cruise includes four gravity-assist flybys of Earth and Venus, which will slingshot the spacecraft towards the outer Solar System. The first flyby of Earth comes in August 2024 and will be the first time a spacecraft will perform a maneuver called a Lunar-Earth gravity assist (LEGA), which involves flying first past the Moon and then past Earth just a day and a half later.

Juice s journey to Jupiter article 1
Juice’s journey to Jupiter. Credit: ESA

Everything about Juice is big. At 4,800 kilograms (10,600 pounds), Juice is one of the heaviest spacecraft ever launched. The complex trajectories also means Juice needed to carry extra fuel, almost 3,000 kilograms (roughly 6,600 pounds) of propellant in total. Over the next two-and-half weeks Juice will deploy its various antennas and instrument booms, including the 16 meter (55 ft)- long radar antenna, 10.6 meter (35 ft)- long magnetometer boom.

Ten state-of-the-art instruments will study the environment of Jupiter and the subsurface of the icy moons. The instruments include radar that can penetrate the surfaces of the icy moons as deep as nine kilometers (six miles), showing us their internal structures for the first time. A visible-and-infrared spectrometer will be able to detect what the surfaces of the icy moons are made of. Two radio instruments will allow scientists to infer the gravity fields of the moons, providing insights into their interiors. And a magnetometer will in particular be focused on Ganymede, as it is the only moon in our Solar System with its own magnetic field.

And if you’re wondering if the name of the spacecraft is Juice or JUICE, ESA decided to simplify the original complicated acronym for JUpiter ICy moons Explorer to just Juice, the Jupiter Icy Moons Explorer.

The post ESA’s Juice is On Its Way to Visit Jupiter’s Moons appeared first on Universe Today.

Continue Reading

Frontier Adventure

ARABSAT BADR-8 Mission Control Audio




This is the vehicle trajectory and mission control audio without any additional commentary. There may be very long periods of silence. For our full hosted webcast, visit

Did you miss our previous article…

Continue Reading

Frontier Adventure

When Black Holes Merge, They’ll Ring Like a Bell



equation 1024x269 1

When two black holes collide, they don’t smash into each other the way two stars might. A black hole is an intensely curved region of space that can be described by only its mass, rotation, and electric charge, so two black holes release violent gravitational ripples as merge into a single black hole. The new black hole continues to emit gravitational waves until it settles down into a simple rotating black hole. That settling down period is known as the ring down, and its pattern holds clues to some of the deepest mysteries of gravitational physics.

Gravitational wave observatories such as the Laser Interferometry Gravitational-Wave Observatory (LIGO) have mostly focused on the inspiral period of black hole mergers. This is the period where the two black holes orbit ever closer to each other, creating a rhythmic stream of strong gravitational waves. From this astronomers can determine the mass and rotation of the original black holes, as well as the mass and rotation of the merged black hole. The pattern of gravitational waves we observe is governed by Einstein’s general relativity equations, and by matching observation to theory we learn about black holes.

General relativity describes gravity extremely well. Of all the gravitational tests we’ve done, they all agree with general relativity. But Einstein’s theory doesn’t play well with the other extremely accurate physical theory, quantum mechanics. Because of this, physicists have proposed modifications to general relativity that are more compatible with quantum theory. Under these modified theories, there are subtle differences in the way merged black holes ring down, but observing those differences hasn’t been possible. But a couple of new studies show how we might be able to observe them in the next LIGO run.

equation 1024x269 2
The modified Teukolsky equation. Credit: Li, Dongjun, et al

In the first work, the team focused on what is known as the Teukolsky Equation. First proposed by Saul Teukolsky, the equations are an efficient way of analyzing gravitational waves. The equations only apply to classical general relativity, so the team developed a way to modify the equations for modified general relativity models. Since the solutions to both the Teukolsky and modified Teukolsky equations don’t require a massive supercomputer to solve, the team can compare black hole ring downs in various gravitational models.

The second work looks at how this would be done with LIGO data. Rather than focusing on general differences, this work focuses on what is known as the no-hair theorem. General relativity predicts that no matter how two black holes merge, the final merged black hole must be described by only mass, rotation, and charge. It can’t have any “hair”, or remnant features of the collision. In some modified versions of general relativity, black holes can have certain features, which would violate the no-hair theorem. In this second work, the authors show how this could be used to test general relativity against certain modified theories.

LIGO has just begun its latest observation run, so it will be a while before there is enough data to test. But we may soon have a new observational test of Einstein’s old theory, and we might just prove it isn’t the final theory of gravity after all.

Reference: Li, Dongjun, et al. “Perturbations of spinning black holes beyond General Relativity: Modified Teukolsky equation.” Physical Review X 13.2 (2022): 021029.

Reference: Ma, Sizheng, Ling Sun, and Yanbei Chen. “Black hole spectroscopy by mode cleaning.” Physical Review Letters 130.2 (2023): 141401.

The post When Black Holes Merge, They’ll Ring Like a Bell appeared first on Universe Today.

Did you miss our previous article…

Continue Reading

Frontier Adventure

There’s a Polar Cyclone on Uranus’ North Pole



Uranus as seen by NASAs Voyager 2.tif e1453247741743

Uranus takes 84 years to orbit the Sun, and so that last time that planet’s north polar region was pointed at Earth, radio telescope technology was in its infancy.

But now, scientists have been using radio telescopes like the Very Large Array (VLA) the past few years as Uranus has slowly revealing more and more of its north pole. VLA microwave observations from 2021 and 2022 show a giant cyclone swirling around this region, with a bright, compact spot centered at Uranus’ pole. Data also reveals patterns in temperature, zonal wind speed and trace gas variations consistent with a polar cyclone.

Uranus as seen by NASAs Voyager 2.tif e1453247741743 1
Uranus as seen by NASA’s Voyager 2. Credit: NASA/JPL

Scientists have long known that Uranus’ south pole has a swirling feature. When Voyager 2 flew past Uranus in 1986, it detected high wind speeds there. However, the way the planet was tilted did not allow Voyager to see the north pole.

But the VLA in New Mexico has now been studying Uranus the past several years, and observations collected in 2015, 2021, and 2022 were able to peer deep into Uranus’ atmosphere. The thermal emission data showed that circulating air at the north pole seems to be warmer and drier, which are the hallmarks of a strong cyclone.

“These observations tell us a lot more about the story of Uranus. It’s a much more dynamic world than you might think,” said Alex Akins of NASA’s Jet Propulsion Laboratory in Southern California, who is lead author of a new study published in Geophysical Letters. “It isn’t just a plain blue ball of gas. There’s a lot happening under the hood.”

The researchers said the cyclone on Uranus is similar to the polar cyclones observed by the Cassini mission at Saturn. With the new findings, cyclones (which rotate in the same direction their planet rotates) or anti-cyclones (which rotate in the opposite direction) have now been identified at the poles on every planet in our solar system that has an atmosphere. The researchers said this confirms a broad truth that planets with substantial atmospheres – whether the worlds are made of rock or gas – all show signs of swirling vortexes at the poles.

Uranus’ north pole is now in springtime. As it continues into summer, astronomers hope to see even more changes in its atmosphere.

The post There’s a Polar Cyclone on Uranus’ North Pole appeared first on Universe Today.

Did you miss our previous article…

Continue Reading