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Happy 25th birthday! Five Reasons the Hubble Space Telescope is Awesome

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Hubble Space Telescope

On April 24 1990, the Hubble Space Telescope was launched into low Earth orbit on board the Space Shuttle Discovery, and deployed the next day. Named after Edwin Hubble, one of the great astronomers of the 20th century, this amazing instrument has offered us hugely important insights into our universe, not to mention some of the most iconic images of outer space ever captured. Even today, after 25 years, Hubble is one of the most famous and most important space telescopes out there. In order to celebrate this great milestone, here’s the story of the legendary telescope in five amazing facts about it.

First of all, the Hubble Space Telescope was a trailblazer. Famed astrophysicist Lyman Spitzer was one of the first to propose an astronomical observatory in space, far from our planet’s thick atmosphere, all the way back in 1946. Then, throughout the 1960s and 1970s he actively lobbied for the development of what would become the Hubble Space Telescope. After a series of delays due to various issues like funding difficulties and the Challenger disaster, Hubble was finally sent into orbit in 1990. Over the next thirteen years, it would be followed by three more powerful telescopes, part of NASA’s Great Observatories program: the Compton Gamma Ray Observatory (1991), the Chandra X-ray Observatory (1999), and the Spitzer Space Telescope (2003). Though all of them have provided scientists with valuable data regarding the Universe, none has even come close to the public profile of Hubble.

Soon after deployment however, a significant problem was discovered. Instead of the sharpest images of space ever taken, scientists were receiving low-quality, blurred photos. The error was eventually found to be a flaw in the 2.4-meter primary mirror, on the order of 2,200 nanometers (about a 50th of the thickness of a sheet of paper). Called a spherical aberration, the flaw meant that the light bouncing off the center of the mirror wouldn’t focus in the same place as the light reflected off the edge. Though the problem was well understood and could be corrected in “post-production,” it was a costly and time-consuming process. Which brings us to the second reason Hubble is awesome: it wears the most expensive pair of glasses of all time!

In December 1993, the first of five servicing missions was launched, which among others contained the Corrective Optics Space Telescope Axial Replacement, or COSTAR. This massive device was about the size of a phone booth and contained a series of mirrors designed to correct the aberration. The cost of the mission was a hefty $500 million, or about a third of the cost of the entire telescope at launch – but it was a complete success and Hubble finally started sending images of the quality scientist had expected all along.

Soon afterwards, scientists got busy using their new toy. The impact of Hubble on the scientific community is difficult to overstate. In its first decade in orbit, 8% of citations to the top-cited astronomy papers were based on Hubble data. Well into the first decade of the 21st century, Hubble Space Telescope papers were being cited tens of thousands of times per year, making it one of the most important scientific instruments in the world.

And it’s not like the data is about some very narrow aspects of astronomy, only professionals would be interested in. Data from Hubble has been used for a whole host of highly significant discoveries, related to everything from the birth of stars and planets, to the evolution of galaxies, measurements of exoplanets and gamma-ray bursts, and observations of gigantic black holes which we now know lurk within the centers of most galaxies. Not only that, but Hubble’s observations of Cepheid variable stars and distant supernovas have provided important insights regarding the rate of expansion of the Universe. The data gathered from the telescope, alongside other ground-based instruments, have led astronomers to believe the expansion of the Universe is accelerating (instead of slowing down, as previously thought). This remarkable finding has actually earned a group of scientists the 2011 Nobel Prize in Physics, and has led others to suggest the existence of dark energy to explain it.

New view of the Pillars of Creation taken by the Hubble Space TelescopeHubble Space Telescope

New view of the Pillars of Creation taken by the Hubble Space Telescope. Revealed in early 2015 to celebrate the Hubble Space Telescope’s 25th birthday, this captivating image shows a stellar nursery, huge clouds of gas four light-years in length, which will event coalesce to form new stars. Image: ESA/Hubble.

But Hubble wasn’t just a highly advanced plaything for professional astronomers. For one thing, at least in the first few years, amateur astronomers could apply for usage of its instruments. But a lot more significantly, NASA soon started taking incredibly beautiful pictures of the Universe, and releasing them to the public. For the first time, perhaps, since the moon landing, the general public could also fully appreciate the work that was being carried out by astronomers. And this is the final point I would like to make about the Hubble Space Telescope: more than any other scientific instrument, it has shown us how awesome the Universe really is. Images like the iconic Pillars of Creation or the Hubble Deep Field are not only relevant to the trained eye of the astronomer, but are also, well, beautiful – more akin to works of art than the cold, dry results of science. No other telescope, not the Large Hadron Collider, nor the International Space Station have managed to captivate the imagination of the public quite like Hubble, and the glimpses it has offered us into the workings of our spectacular Universe.

Hubble Ultra Deep Field

The Hubble Ultra Deep Field. Each dot in this picture, which shows just a tiny, dim part of the sky, is a galaxy. In total, there are about 10,000 of them, ranging in age from one billion to 13 billion years old. Image: ESA/Hubble.

The Hubble Space Telescope has long outlasted its initial service duration estimates. Over the years, five service missions have been deployed to correct flaws and upgrade instruments, so even after a quarter of a century Hubble is still going strong – in fact, it’s more powerful than ever, and is expected to be fully operational at least until 2020. Here’s hoping it’s going to be a long and productive journey!

Who doesn’t enjoy listening to a good story. Personally I love reading about the people who inspire me and what it took for them to achieve their success. As I am a bit of a self confessed tech geek I think there is no better way to discover these stories than by reading every day some articles or the newspaper . My bookcases are filled with good tech biographies, they remind me that anyone can be a success. So even if you come from an underprivileged part of society or you aren’t the smartest person in the room we all have a chance to reach the top. The same message shines in my beliefs. All it takes to succeed is a good idea, a little risk and a lot of hard work and any geek can become a success. VENI VIDI VICI .

Astronomy

NASA’s flyby of Europa shows that “something” is moving under the ice

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Europa’s surface has marks that show the icy crust is vulnerable to the water below. The most important thing is that Juno’s recent visit shows what might be plume activity. If this is real, it would let future missions take samples of the ocean inside the planet without having to land.

Even though it’s been almost two years since Juno got the closest to Europa, its data is still being looked at. Even though Juno has been going around Jupiter since 2016, the five pictures it took on September 29, 2022, were the closest views of Europa since Galileo’s last visit in 2000.

Some might say that’s a shocking lack of interest in one of the Solar System’s most interesting worlds, but it could also have been a good way to see how things had changed over time.

Europa is the smoothest object in the solar system because its ocean keeps it from sinking to the surface. Still, it’s not featureless; Juno saw some deep depressions with steep walls that are 20 to 50 kilometers (12 to 31 miles) wide, as well as fracture patterns that are thought to show “true polar wander.

In a statement, Dr. Candy Hansen of the Planetary Science Institute said, “True polar wander occurs if Europa’s icy shell is separated from its rocky interior. This puts a lot of stress on the shell, which causes it to break in predictable ways.”

The shell that sits on top of Europa’s ocean is thought to be rotating faster than the rest of the moon. This is what true polar wandering means. People think that the water below is moving and pulling the shell along with it. Ocean currents are thought to be causing this. The currents are most likely a result of heat inside Europa’s rocky core, which is heated up as a result of Jupiter and its larger moons pulling on Europa and turning it into a large stress ball.

The ocean and ice could stretch and compress parts of the ice, which is how the cracks and ridges that have been seen since Voyager 2 visited were made.

A group under the direction of Hansen is viewing images of Europa’s southern half. The scientist said, “This is the first time that these fracture patterns have been mapped in the southern hemisphere. This suggests that true polar wander has a bigger effect on Europa’s surface geology than was thought before.”

Ocean currents are not to blame for all of Europa’s map changes. It appears that optical tricks can even fool NASA. Hansen said, “Crater Gwern is no longer there.” “JunoCam data showed that Gwern, which was once thought to be a 13-mile-wide impact crater and one of Europa’s few known impact craters, was actually a group of ridges that crossed each other to make an oval shadow.”

But Juno gives more than it takes away. The team is interested in what they’re calling the Platypus because of its shape, not because it has a lot of parts that shouldn’t go together. Ridges on its edge look like they are collapsing into it. The scientists think this might be because pockets of salt water have partially broken through the icy shell.

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The Europa Clipper would find these pockets to be fascinating indirect targets for study, but the dark stains that cryovolcanic activity might have left behind are even more intriguing.

“These features suggest the possibility of current surface activity and the existence of liquid water beneath the surface on Europa,” stated Heidi Becker from the Jet Propulsion Laboratory. There is evidence of such activity in the geysers of Enceladus, but there is still uncertainty regarding whether it is currently happening on Europa.

Engaging in such an endeavor would enable the sampling of the interior ocean to detect signs of life simply by flying through a plume and gathering ice flakes without the need for landing or drilling.

It seems that in the past, there was a significant shift of over 70 degrees in the locations of features on Europa’s surface, although the reasons for this remain unknown. However, at present, polar wander only leads to minor adjustments.

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Astronomy

The Sun emitted the largest solar flare in the past 20 years, resulting in power outages

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Solar Cycle 25 is decidedly more turbulent than its predecessor. The Sun is currently experiencing heightened activity, characterized by solar storms, coronal mass ejections, and geomagnetic storms of unprecedented intensity in recent years. Currently, the sun has emitted its most powerful solar flare to date during this particular cycle.

The flare was quantified as an X8.7, indicating a considerably higher strength compared to the flares emitted last week. The event emitted highly energetic light in the extreme ultraviolet range, which resulted in the ionization of the uppermost layer of the atmosphere. Consequently, a radio blackout occurred over the Americas, adversely impacting aircraft and vessels that depend on signals with frequencies below 30 MHz.

Ionization of the atmosphere causes an expansion, resulting in increased drag on satellites in low Earth orbit. They will require strategic maneuvering to be moved away from Earth. Solar flares have the potential to interfere with satellite communications.

A gif of the Sun yesterday with two bright flashes corresponding to the flares on its limb

Sunspot AR 3664 is where it comes from. Last week, several strong flares were seen coming from this area, including the second strongest of this cycle at the time. The Sun also sent out a number of coronal mass ejections (CMEs), which hit Earth and caused the beautiful auroral display we saw last weekend.

Back then, the sunspot was right on the side of the Sun that could be seen, and anyone could see it. It’s sixteen times wider than Earth! As the Sun turns, the spot is now on its side, so we can only see it from the side. We might have seen a bigger flare if it had happened last week.

“Another X-ray flare was made by Region 3664 as it moved past the western solar limb!!” It was an X8.7 flare this time, the biggest of this solar cycle! NASA’s Space Weather Prediction Center said in a post that any coronal mass ejection (CME) linked to this flare “likely WILL NOT have any geomagnetic effects on Earth due to its location.” “As always, please check our website for news!”

Today, as the CME moves past Earth, there may be a small rise in auroral activity. It’s too bad that nothing as exciting will happen as last Friday.

The solar cycle has a high point and a low point every 11 years. Around the peak, which could happen at any time, the most intense events tend to happen, but every once in a while, there are exceptions. There have been 10 times as many powerful flares this century.

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Astronomy

This planet like Earth is the first one that has been proven to have an atmosphere

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Astronomers have successfully utilized the James Webb Space Telescope (JWST) to observe the presence of an atmosphere around a terrestrial exoplanet, marking the first such discovery beyond our solar system. Despite its inability to sustain life due to its likely magma ocean, this planet could provide valuable insights into the early geological development of Earth, as both planets share a rocky composition and a history of being molten.

Sara Seager, a planetary scientist at the Massachusetts Institute of Technology in Cambridge who was not part of the study, states that the discovery of a gaseous envelope surrounding an Earth-like planet is a significant achievement in the field of exoplanet research. The Earth’s tenuous atmosphere plays a vital role in supporting life, and the ability to detect atmospheres on comparable rocky planets is a significant milestone in the quest for extraterrestrial life.

JWST is currently studying the planet 55 Cancri e, which orbits a star similar to the Sun at a distance of 12.6 parsecs. It is classified as a super-Earth, meaning it is a terrestrial planet slightly larger than Earth. Specifically, it has a radius approximately twice that of Earth and a mass more than eight times greater. The paper published in Nature1 suggests that the atmosphere of the planet is likely to contain significant amounts of carbon dioxide or carbon monoxide. Additionally, the thickness of the atmosphere is estimated to be “up to a few percent” of the planet’s radius.

A mysterious world
55 Cancri e is also not a good place to live because it is very close to its star—about 1.6 times as close as Earth is to the Sun. Still, Aaron Bello-Arufe, an astrophysicist at the Jet Propulsion Laboratory (JPL) in Pasadena, California, and a co-author of the paper, says, “it’s perhaps the most studied rocky planet.” Its host star is bright at night, and the planet is big for a rocky one, so it’s easier to study than other places outside of the Solar System. “In astronomy, every telescope or other tool you can think of has pointed to this planet at some point,” says Bello-Arufe.

55 Cancribe was studied so much that when JWST was launched in December 2021, engineers pointed the infrared spectrometers of the spacecraft at it to test it. As these instruments soak up infrared wavelengths from starlight, they can find the chemical signatures of gases swirling around planets. Then Bello-Arufe and his coworkers chose to look into it more to find out for sure if the planet had an atmosphere.

Astronomers had changed their minds about 55 Cancri a huge number of times before the most recent observations. In 2004, the planet was found. Scientists first thought it might be the center of a gas giant like Jupiter. Researchers looked at 55 Cancri e as it passed in front of its star3 with the Spitzer Space Telescope in 2011. They found that it is a rocky super-Earth, much smaller and denser than a gas giant.

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After some time, scientists found that 55 C was cooler than it should have been for a planet that was so close to its star. This suggests that it probably has an atmosphere. One hypothesis was that the planet is a “water world” with supercritical water molecules all around it. Another was that it has a large, primordial atmosphere mostly made up of hydrogen and helium. But in the end, these ideas were shown to be wrong.

According to Renyu Hu, a planetary scientist at JPL and co-author of the new study, stellar winds would make it difficult for a planet this close to its star to retain volatile molecules in its atmosphere. He says there are still two options. The first was that the planet is completely dry and has a very thin layer of rock vapor in the air. The second reason was that it has a thick atmosphere made up of heavier, less volatile molecules that don’t easily escape.

A better picture
The most recent information shows that 55 Cancrie’s atmosphere has gases made of carbon, which points to option two. Seager says that the team did indeed find evidence of an atmosphere but that more observations are needed to fully understand its make-up, the amounts of gases present, and its exact thickness.

Laura Schaefer is a planetary geologist at California’s Stanford University. She wants to know how the atmosphere of 55 Cancrie affects things below the surface of the planet. The authors of the study say it’s still possible that stellar winds are carrying away parts of the atmosphere. However, rocks melting and releasing gases into the magma ocean could replace the gases.

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