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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

The Eta Aquariids meteor shower is occurring this month, and its peak can be observed at a specific time

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Currently, Earth is undergoing one of its three most active meteor showers. The Eta Aquariids, remnants of Halley’s comet, are observed during the month of May. During this period, Earth approaches the comet’s orbit at a distance of approximately 9.7 million kilometers (6 million miles), which is close enough to collect residual dust particles.

The Eta Aquariids exhibit a frequency of up to one meteor per minute, although this level of activity is limited to individuals residing near the equator and in the southern tropics. For the rest of the population on Earth, it is anticipated that there will be a more moderate but still highly respectable rate of 10 to 30 meteors per hour. The optimal time in the Northern Hemisphere is during the pre-dawn period when the sky is at its maximum darkness, particularly in areas located away from urban centers. The midnight hours are also favorable in the Southern Hemisphere.

Allow approximately 30 minutes for your eyes to adapt; thus, it is important to take this into account. The duration of the meteor shower spans from April 19 to May 28 annually. The zenith of meteor activity is anticipated to occur during the nights of May 5th and 6th; however, there is a high probability of observing numerous meteors throughout the entire week.

Our orbit intersects with the orbit of Halley’s comet twice annually. In May, this event results in the occurrence of a meteor shower. In October, the remnants form the Orionid meteor shower. The Eta Aquariids derive their name from their origin at the star Eta Aquarii.

Halley’s comet exhibits significant luminosity and possesses a comparatively brief orbital period, completing one revolution around the sun every 76 years. For a period of more than 2,250 years, humans have been engaged in the act of observing it. The earliest documented sighting of this phenomenon occurred in 240 BCE and was recorded in the Book of Han by Chinese astronomers in 12 BCE. The year 1066 witnessed the depiction of this event in two significant historical records: the Bayeux Tapestry, which documented the Norman Conquest of England, and the petroglyphs created by the Chaco, indigenous Americans in present-day New Mexico.

The appearance of a comet in 1301 inspired Giotto di Bondone to depict the Star of Bethlehem as a comet, which had a lasting influence on its portrayal for the next seven centuries. Although observations had been made for thousands of years, it was not until 1705 that Edmond Halley discovered the periodicity of them.

The most recent observation of the object from Earth occurred in 1986, and it is expected to return to the inner solar system in 2061. Currently, it is returning to its original position after reaching its maximum distance from the sun in December.

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Astronomy

NASA and ESA are making preparations for the imminent close approach of the near Earth object Apophis

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NASA and the European Space Agency (ESA) are making preparations for the imminent approach of asteroid 99942 Apophis, a near-Earth object.

Apophis, an asteroid considered highly dangerous to Earth, will approach within 32,000 kilometers (20,000 miles) of the Earth’s surface in 2029. This close encounter will allow scientists to closely examine the object. The asteroid will be visible from the Eastern Hemisphere without the need for a telescope or binoculars, and it will be closer than some of our man-made satellites.

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At the ESA-organized workshop Apophis T-5 Years: Knowledge Opportunity for the Science of Planetary Defense, scientists have been proposing potential missions to investigate the asteroid prior to the close approach.

NASA has already scheduled a visit to the asteroid, which is known as OSIRIS APEX. The objective is to reutilize the asteroid sampler previously referred to as OSIRIS-REx, deploying it to rendezvous with the asteroid soon after its close passage.

“According to NASA, the planned mission is expected to result in the alteration of the asteroid’s orbit, changes in its rotational speed and axis, and the potential occurrence of quakes or landslides that will modify its surface due to the gravitational pull of our planet,” NASA explains. The OSIRIS-APEX mission will enable terrestrial scientists to observe these alterations. In addition, the OSIRIS-APEX spacecraft will descend towards the surface of Apophis, an asteroid composed of silicate material (also known as rocky material) and a combination of metallic nickel and iron. It will then activate its engines to dislodge loose rocks and dust. This maneuver will provide scientists with a glimpse into the composition of the material located directly beneath the surface of the asteroid.

According to Space News, private companies presented alternative missions for the asteroid at the ESA meeting.

Blue Origin plans to utilize its Blue Ring spacecraft to transport a maximum of 13 payloads, weighing a combined total of 2 metric tons, to the asteroid. The launch is scheduled for 2027, with the spacecraft reaching the asteroid just before it comes closest to Earth. Meanwhile, NASA’s Jet Propulsion Laboratory presented the details of its DROID mission, which focuses on distributed radar observations of interior distributions.

JPL explains in a proposal that the architecture of DROID requires a specific launch of three spacecraft: a Mothership of ESPA Grande-class and two CubeSats. The Mothership transports the CubeSats to Apophis, follows a planned trajectory to meet up with them, captures detailed images using a specialized camera, and serves as a communication hub for the constellation by directly relaying data to Earth. After thoroughly characterizing Apophis’s physical attributes, such as its shape, spin, and gravity field, the Mothership releases two CubeSats. Each CubeSat is equipped with a wide-angle camera and low-frequency radar (operating at 60 MHz, using JuRa technology). These CubeSats then position themselves in synchronized low orbits to conduct radar observations using both monostatic and bistatic techniques.

Although the flyby of Apophis is expected to provide valuable insights into planetary defense against similar objects, there is no reason to be alarmed by its presence.

In 2021, Apophis conducted a close approach to Earth, during which astronomers conducted high-resolution radar observations to more accurately determine its orbital path. Prior to that, NASA held the belief that there was a possibility of a collision occurring later in the century. However, the observations conducted have definitively disproven this hypothesis.

“The possibility of a 2068 impact is no longer feasible,” stated Davide Farnocchia, an expert from NASA’s Center for Near-Earth Object Studies. “Our calculations indicate that there is no risk of impact for at least the next 100 years.”

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Astronomy

NASA has recently received a laser message transmitted from a massive distance of 226 million kilometers

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NASA’s Psyche mission is currently en route to investigate an unusual asteroid, and while in transit, the mission team has been conducting trials of a novel communication system. The novel methodology employs an infrared laser instead of radio waves, and it has recently demonstrated its efficacy from the farthest location to date. The message was sent when Psyche was located at a distance of 226 million kilometers (140 million miles) from Earth. That is equivalent to 1.5 astronomical units, which is the distance between the Earth and the Sun.

Psyche was transmitting its engineering data via radio waves using NASA’s Deep Space Network. For the first time, the mission team made the decision to transmit the data using the Deep Space Optical Communication system. The previous transmissions did not contain spacecraft data but rather test data.

During the April 8 test, it was demonstrated that data could be downloaded at a maximum rate of 25 Mbps, even from that distance. This already exceeds the anticipated target of “at least 1 Mbps” and is 10 to 100 times swifter than radio transmissions.

“During a pass on April 8, we received approximately 10 minutes of replicated spacecraft data through downlink,” stated Meera Srinivasan, the operations lead for the project at NASA’s Jet Propulsion Laboratory (JPL). Previously, we had been transmitting test and diagnostic data through our downlinks from Psyche. This marks a noteworthy achievement for the project as it demonstrates the integration of optical communications with a spacecraft’s radio frequency communications system.

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In previous tests, the spacecraft was positioned at a much shorter distance, specifically tens of millions of kilometers. Photographs and even a video featuring a cat were transmitted from the far reaches of outer space. The technology exhibits potential, yet there remain a few issues that require resolution. Clouds obstruct optical observations, preventing them from being conducted. This issue doesn’t affect radio communications.

“We have gained extensive knowledge about the system’s limits through our experiments during clear weather conditions. However, occasional storms have caused disruptions in operations at both Table Mountain and Palomar,” stated Ryan Rogalin, the receiver electronics lead of the project at JPL.

In June, the team will conduct another round of testing on the system when Psyche is located at a distance from the Sun that is 2.5 times greater than the distance between Earth and the Sun. This represents the utmost distance separating Mars and Earth. If the approach is successful, it could enable the establishment of a data-intensive network connecting Earth and Mars.

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