Latest news with #EdwinHubble
Forbes
4 days ago
- General
- Forbes
Our Milky Way May Not Collide With Andromeda After All, Scientists Say
Andromeda Galaxy : Milky Way Galaxy : ... More Stars : When will the Milky Way collide with the Andromeda Galaxy? It's a common question because, for many years, astronomers have theorized that the two largest spiral galaxies in our cosmic neighborhood — our Milky Way and Andromeda (also called M31) will one day collide. An answer is normally offered: about four billion years. Now, this decade-long belief is being challenged by new research that suggests the Milky Way and Andromeda may not be on a collision course after all. The study, published today in Nature Astronomy, reveals a 50% probability that the two galaxies will avoid crashing into each other within the next 10 billion years. Andromeda is 2.5 million light years from the Milky Way. Cmosmically speaking, that's very close. It's home to at least a trillion stars. The Milky Way, meanwhile, hosts about 100-400 billion stars (it's hard to say because we're in it, so our telescopes can't see all of it). The knowledge that Andromeda is moving toward the Milky Way is core to our understanding of an expanding universe. Having four years previously figured out that Andromeda — a fuzzy blob to the naked eye in dark skies — was an "island universe" (in other words, a galaxy), American astronomer Edwin Hubble calculated in 1929 that galaxies were moving away from the Milky Way, All of them, that is, except one — Andromeda. The universe was expanding, as Albert Einstein had predicted. However, Andromeda and the Milky Way are headed towards each other at 250,000 miles per hour. Three future scenarios for Milky Way & Andromeda encounter. Top left: Galaxies bypass at 1 million ... More light-year separation. Top right: At 500,000 light-years, dark matter provides friction that brings galaxies to a close encounter. Bottom: A 100,000 light-year separation leads to a collision. Andromeda will dominate Earth's night sky in about four billion light-years, goes the received wisdom. It will collide with the Milky Way in about five billion years, forming a new, larger galaxy — 'Milkomeda.' New research debunks this. Based on gravitational models that consider the influence of other celestial bodies in the Local Group of galaxies — specifically a number of dwarf galaxies orbiting the Milky Way — researchers at the University of Helsinki in Finland calculate that the Milky Way's path through the cosmos has a high chance of missing Andromeda altogether. The research uses the latest data from the European Space Agency's Gaia mission and NASA's Hubble Space Telescope, along with revised mass estimates of surrounding galaxies. The Milky Way is not alone. It exists with over 50 other galaxies called the Local Group, which also includes Andromeda. In orbit around the Milky Way are a number of dwarf galaxies, including the Small and Large Magellanic Clouds and the Triangulum galaxy (M33) — the latter half the size of our Milky Way and the third-largest galaxy in our local group of galaxies, according to NASA. Those small galaxies affect the Milky Way's path through space, according to the researchers, whose new data on the mass of those galaxies produces a new result. In particular, the gravitational pull of the LMC, whose mass was not considered in previous analyses, may explain it. As an aside, this paper also states that the LMC may merge with the Milky Way within the next two billion years. The Andromeda Galaxy. (Photo by: Alan Dyer /VW PICS/Universal Images Group via Getty Images) Given that the movement of Andromeda is the basis for our understanding of the entire universe, there's been a lot of research into its movements. In 2019, researchers reported that Andromeda had already consumed several smaller galaxies within the last few billion years. In 2023, another paper argued that the Milky Way and Andromeda are, in effect, already interacting since ancient stars in the Milky Way's halo are about halfway to Andromeda and that a halo of gas around both galaxies is already entwined. Whether or not Andromeda collides with the Milky Way or not in four billion years is, for Earthlings, somewhat academic. By that time, the sun will have used up its hydrogen fuel and be expanding into a red giant star, boiling away Earth's oceans as it does so and possibly even consuming the entire planet. Wishing you clear skies and wide eyes.
Yahoo
21-05-2025
- Science
- Yahoo
Astronomers Spot a Strangely Perfect Sphere Thousands of Light-Years Away
Here's what you'll learn in this story. Scientists using radio wavelength data from the Australian Square Kilometre Array Pathfinder (ASKAP) spotted a strangely symmetrical sphere located thousands of light-years away. The 'sphere' is likely the result of a Type 1a supernova shockwave, though astronomers aren't sure exactly how far away the this supernova remnant is from Earth—either 7,175 light-years or 25,114 light-years. Regardless of this distance discrepancy, the near-perfect spherical nature of the remnant gives scientists the opportunity to learn more about one of the most energetic events in the universe. The amount humanity has learned about the cosmos in just the past century is truly staggering. A little over a century ago, American astronomer Edwin Hubble announced to the world that the Milky Way was actually just one galaxy among many in the known universe. Now, we know the universe contains hundreds of billions—if not trillions—of galaxies, and engineers have developed space-based telescopes capable of spying some of the oldest ones in existence. Of course, that doesn't mean mysteries don't remain—both large and small. On the big side of the equation, dark matter and dark energy remain perplexing conundrums, but science's array of detectors often posit smaller puzzles. One such mystery is the curious case of supernova remnant (SNR) G305.4–2.2, nicknamed Teleios. A Greek word meaning 'perfect,' Telelios references the near-perfect symmetry of what appears to be a sphere of ejected star material—aka a supernova remnant. Initially captured by the Australian Square Kilometre Array Pathfinder (ASKAP), Teleios's origin isn't the real head-scratcher. Instead, scientists like Miroslav Filipović, an astrophysicist from Western Sydney University in Australia, are more perplexed by its near-perfect shape, an extreme rarity for such an SNR throughout the universe. 'The supernova remnant will be deformed by its environment over time,' Filipovic, along with a cadre of other Australian astrophysicists, wrote in an article on The Conversation in March. 'If one side of the explosion slams into an interstellar cloud, we'll see a squashed shape. So, a near-perfect circle in a messy universe is a special find.' In an analysis submitted to the Publications of the Astronomical Society of Australia and published on the preprint server arXiv, Filipović—the lead author of the study—and his team discovered that Teleios only glows faintly in radio wavelengths. Armed with this information, the astronomers could reasonably deduce that Telelios originated from a Type 1a supernova, which typically form from binary star systems where one of the stars is a white dwarf. Because these types of supernovae are consistent in their peak brightness, astronomers have used them for decades to measure cosmic distances (with none other than the Hubble telescope among others). However, in this instance, astronomers haven't been able to quite nail down Teleios's exact distance, but they've drawn up three best guesses. If it is the results of a Type 1a supernova, then its likely that this symmetrical mystery is either 7,175 light-years or 25,114 light-years away, making the sphere either 46 light-years across or 157 light-years across, respectively. This distance also reflects its age, meaning it's either less than 1,000 years old or greater than 10,000 years old. So, lots of room for further exploration. The study also posits the idea that it could be a Type 1ax supernova where the supernova instead leaves behind a 'zombie star' remnant, according to Live Science. However, in this scenario, the supernova would be only 3,262 light-years away and around 11 light-years across. Whatever the scenario, Teleios—which is just one of the many interesting things discovered by ASKAP—still presents a remarkable opportunity to learn more about supernovae. 'This presents us with an opportunity to make inferences about the initial supernova explosion, providing rare insight into one of the most energetic events in the universe,' Filipovic co-authors in The Conversation. In 100 years from now, who knows what the universe might look like to our 22nd-century enlightened minds. You Might Also Like The Do's and Don'ts of Using Painter's Tape The Best Portable BBQ Grills for Cooking Anywhere Can a Smart Watch Prolong Your Life?
The Hindu
05-05-2025
- Science
- The Hindu
Hubble's 35-year journey is a blueprint to understand the cosmos
From breathtaking snapshots of distant galaxies to game-changing discoveries about the universe's expansion, the Hubble Space Telescope (HST) has dazzled humankind for 35 years. After launching on April 24, 1990, Hubble overcame early flaws to become one of NASA's greatest triumphs. Its vivid images and countless scientific breakthroughs have reshaped our understanding of the cosmos, inspiring new generations of telescopes and astronomers. To celebrate Hubble's majestic journey for more than three decades, NASA recently released a collection of striking images captured by the HST. The US astronomer Lyman Spitzer proposed the idea of the Large Space Telescope in the 1940s. NASA and the US Congress approved the project in 1969 but faced budget pressures. Then the European Space Agency chipped in with 15% of the LST's cost in exchange for 15% of its observation time. The HST, named for astronomer Edwin Hubble, was planned in 1979 and built by 20 companies, universities, and the European Space Agency. It was initially scheduled to be launched in 1986 but that was delayed until 1990 due to technical difficulties and the Space Shuttle Challenger disaster. The HST first had two cameras: the Wide-Field and Planetary Camera (WFPC) and the Faint Object Camera. It also had two spectrographs: the Goddard High-Resolution Spectrograph (GHRS) and the Faint Object Spectrograph (FOS). A high-speed photometer onboard detected light from high-energy sources. Three fine-guidance sensors installed in 1990 made high-precision measurements of the positions of celestial objects. The WFPC was the most popular. It consists of two cameras. The Wide-Field camera covered large sky areas while the Planetary Camera magnified and improved image resolution. The Faint Object Camera captured light from distant celestial objects with help from an image intensifier. Scientists and engineers took several weeks to check the HST's control and communication systems before astronomers working at the Space Telescope Science Institute in Baltimore could see its first images. Shortly after launch, the HST's photos were blurred, later found to be because the telescope's mirror had been ground to the wrong shape. Ground team members soon came up with a corrective device: a series of smaller mirrors called COSTAR to compensate for the primary mirror's defect. Astronauts launched in 1993 implemented this fix on the HST, by that time in earth orbit. They removed the high-speed photometer to make way for COSTAR, as well as replaced the WFPC with the WFPC 2, among other upgrades. The telescope experienced a similar problem in 1997. The analysis of light is of great importance in space research. Blue light has a shorter wavelength and red light has a longer wavelength. If the frequency of incoming light bluer, it means the light source is moving towards the observer. If the frequency is becoming redder, the object is moving away. The HST's GHRS and FOS devices, which perform this analysis, worked well until 1997. NASA subsequently replaced them with the Space Telescope Imaging Spectrograph that year. This device can analyse frequencies of light from the ultraviolet to the infrared. The telescope's antenna transmits approximately 150 Gb of data a week. According to NASA, the HST has observed almost 52,000 stellar objects in 1.6 million observations since launch. One of the HST's most significant achievements was to get scientists the data with which they estimated the universe's age. Before the telescope came along, astronomers didn't know if the universe was 10 billion years old or 20 billion. To get the answer, astronomers looked at the Cepheid variable stars — a type of star that pulsed in a steady way, its brightness varying over periods of days or months. Astronomers could determine the distance to such a star using its luminosity and pulsation rate. Based on that measurement, they could then estimate the distances to various other, more distant celestial objects. Finally, based on all the data, astronomers could estimate how fast the universe was expanding, and work back from there to the universe's age. With the HST's keen observations, they identified more than 800 Cepheid stars in 24 galaxies and thereon that the universe was around 13.8 billion years old. Astronomers have also created a 3D map of dark matter using data from the HST and other telescopes. The telescope has also found that gamma-ray bursts, the universe's most energetic explosions, occur in galaxies with rapid star formation and a low proportion of elements heavier than helium. Numerous galaxies had supermassive black holes at their centres — or so astronomers believed by the early 1990s, and the HST the belief's underlying assumptions. Closer home, the HST helped find two additional moons of Pluto (Nix and Hydra) and observed seasonal alterations on Pluto's surface. Its data helped estimate the mass of Eris, the solar system's heaviest dwarf planet, and based on that indicated the existence of more such objects in the Kuiper Belt and beyond. The HST also first studied the atmosphere of an exoplanet: HD 209458-b, a.k.a. Osiris, a hot world located 150 lightyears away. Osiris was found to be within 6.4 million km of its host star and thus a surface temperature of around 1,100° C. The HST was initially expected to operate for 15 years but it has consistently delivered over the last 35 years and continues to do so. Astronomers commemorated the anniversary of its launch with a stunning image of NGC 1333, a star-forming area located 967 light-years away in the Perseus molecular cloud. It is impossible to overstate the HST's pride of place in our understanding of the cosmos. Every pixel of its images has revealed whole new worlds in the great beyond, helping us understand our own place in the cosmos. Shamim Haque Mondal is a researcher in the Physics Division, State Forensic Science Laboratory, Kolkata.
Yahoo
26-04-2025
- Science
- Yahoo
How Old Is the Universe? A Massive Cosmic Mystery, Explained
"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." —Douglas Adams, The Hitchhiker's Guide to the Galaxy Observatories like the Hubble Telescope and the James Webb Space Telescope offer humanity the power to see things farther away than ever before. When we look deeply into the night sky, we also look back in time. Compared with the universe as a whole, Earth is quite young at 4.5 billion years old. Scientists arrived at this number because of evidence from radiometric dating, which measures the rate of radioactive decay in elements with known half-lives. Moon rocks, ancient zircons, meteorites—they all say the same thing: Earth is 4.5 billion years old. But from where Earth sits in the observable universe, our view extends more than 13 billion years into the past. Far outside our Local Group, astronomers have found galaxies so metal-poor and so deeply redshifted that they appear to have formed less than 300 million years after the Big Bang, the beginning of our known universe. Just how long has the universe been around? Scientists estimate the universe is 13.8 billion years old, with an uncertainty of plus or minus just two percent. But how do we know? In 1924, observing the night sky through what was then the world's largest telescope, cosmologists including Edwin Hubble and Georges Lemaître reported that almost every galaxy was moving away from Earth. Moreover, the farther away the galaxies were, the faster they were moving away. Subsequent observations by Hubble's eponymous space telescope and the JWST have confirmed this relationship between distance and speed. Not only are most galaxies moving away from Earth, but they're also moving away from one another, with speed proportional to how far they are apart. Edwin Hubble based his distance calculations on a cosmological "standard candle" called Cepheid variables: stars whose brightness is strongly and directly related to their pulsation period. Cepheid variables are an important rung on the cosmic distance ladder, a system astronomers use that builds one observation on another to draw logical conclusions about things much farther away than our telescopes can resolve. Astronomers in ancient Greece had already figured out that for two stars of the same type, the more distant one will be smaller in the sky, but they didn't know what we know now: some types of stars are larger than others at a given brightness. Because we know the true luminosity of Cepheid variables, we can precisely calculate their distance. That lets us measure the distance to objects very far away. Light from our own sun has a shorter wavelength when emitted from the side of the solar disc that's rotating toward us, and a longer wavelength on the side that's rotating away from Earth. This phenomenon, known as the Doppler effect, is the same thing that changes the sound of a siren as it approaches and departs. Hubble and his contemporaries noticed that rotating stars and galaxies whose proper motion is moving them in relation to the Earth also show this effect, stretching or squashing the wavelength of their light depending on whether they're coming closer or moving away. The more pronounced the Doppler shift, the faster a thing is moving. With enough measurements of distance and recession velocity, cosmologists can calculate the rate at which spacetime is expanding: H0. But if galaxies are moving farther apart, they must have started closer together. As their paths converge, we can see where and when they started in the first place. From there, scientists can rewind cosmic time, running the clock backward to estimate the universe's maximum age. Time begins for us at the moment of the Big Bang, when in a tiny fraction of a second, an explosion of incomprehensible magnitude cast outward a huge amount of matter and energy. During the first few picoseconds after the Big Bang, the laws of physics were very different from those in our frame of reference. As the primordial gluon soup expanded outward, it cooled, but to do that, it had to push out the boundaries of the observable universe. Credit: ESA – C. Carreau After the Big Bang, for the first 380,000 years or so, the universe was so hot and dense that it was effectively opaque. Like the core of a star, electrons were crammed so tightly together that photons couldn't go anywhere. As the universe cooled and expanded, suddenly, photons could find paths outward. Spacetime itself released the photons in a titanic burst of radiation, the last traces of which we see as the cosmic microwave background: the fading glow of residual radiation left over from the Big Bang after all this time. Credit: ESA/Planck Collaboration Some CMB photons are polarized, meaning that as they travel outward from their source, they vibrate in a "preferred" direction. Patterns in the polarization tell astronomers about the last interaction between those photons and the electrons that trapped them long ago, because in the places where there were the most electrons, matter was most densely concentrated. All of the above leads us to believe we have a pretty solid idea about how old the universe is. As our telescope technology improves, uncertainty in our models decreases. But because nothing's easy in cosmology, there are some discrepancies. Light appears to obey a kind of cosmic speed limit abbreviated as c, which was an integral part of Einstein's theory of relativity. However, spacetime itself may not be subject to the same speed limit. The universe is 13.8 billion years old, but the radius of the observable universe isn't 13.8 billion light-years. Instead, the observable universe is some 46.5 billion light-years across. This is because the fabric of spacetime has expanded since the light we see left its distant sources. Its rate of expansion tells us about its age, but our primary methods of measuring that rate return different answers. The prevailing model of cosmology, called the lambda-CDM model (lambda for the cosmological constant; CDM for cold dark matter—more on this in a moment), imposes an upper boundary for the age of the universe: 14.5 billion years, tops. In this model, dark matter and dark energy are crucial to explaining the structure of the universe on the largest scales. But the model also has to account for the cosmic microwave background and the change in the universe's rate of expansion. Therein lies the rub. Different observational sources also give slightly different values for the age of the universe. This discrepancy is a cosmological problem known as the Hubble tension. Still, the difference is very small. For example, the European Space Agency's Planck mission, a space telescope launched to observe the cosmic microwave background, returned data that points to an age of 13.787 billion years. Meanwhile, NASA's Wilkinson Microwave Anisotropy Probe (WMAP) project calculated the universe to be 13.772 billion years old. The universe has to be at least as old as the oldest thing in it. The oldest observed galaxies are deeply redshifted (z = 11 or greater), and may have formed within a few hundred years of the Big Bang. Light from these objects has traveled more than 13 billion light-years to reach us. For the universe to be older than about 14 billion years, we'd have to throw out most of the assumptions from the lambda-CDM model, which otherwise fits observational evidence. However, a 2023 paper calculates the age of the universe as roughly twice that—26.7 billion years old. What gives? The paper's logic rests on a phenomenon called "tired light," which physicist Fritz Zwicky proposed in 1929 to explain the redshifting of photons from distant sources. Photons from a source moving away from us appear to change on their way here. Their wavelength increases, which we see as a shift in color toward the red. Light from a source that's approaching Earth, meanwhile, appears to shift toward the higher-energy, "bluer" end of the spectrum. Current cosmology explains this redshift as a product of the expansion of space itself, fast enough to stretch out the wavelength of a photon moving through it. In the century since Hubble's initial report, thousands of surveys investigating millions of stars and galaxies have borne out his and his colleagues' observations—and substantiated the theory of relativity beyond reasonable doubt. But Zwicky's "tired light" proposes that the photons lose energy as they travel through spacetime. Rajendra Gupta, a physicist from the University of Ottawa and the author of the 2023 "tired light" paper, acknowledges that tired light theory conflicts with observations. However, Gupta said, "By allowing this theory to coexist with the expanding universe, it becomes possible to reinterpret the redshift as a hybrid phenomenon, rather than purely due to expansion." In other words, we don't know what we don't know. Uncertainty in our measurements of the age of our universe and the fact that the Hubble tension exists don't invalidate our measurements. They do show us that our grand models need some unifying. Right at the front of the line, there's the lambda-CDM model. Dark matter is still a dark horse, and that's another problem. It's still hotly debated how dark matter figures into the grand scheme of things—or if there's any such thing as dark matter, or dark energy, in the first place. Some astronomers have proposed a system of modified Newtonian dynamics as an alternative to cold dark matter, or even more exotic models including brane cosmology, which is related to string theory. Still, understanding dark matter will require some extraordinary evidence: many observations of candidate dark-matter particles and some shiny new physics models to explain them. Whether dark matter pans out as a theory will also affect our expectations about the long-term behavior of the universe. The rate at which the universe is expanding has implications for its ultimate fate: heat death, a Big Rip, eventual collapse into a new all-encompassing singularity, or something else altogether. If the universe is expanding at a constant rate, in equilibrium with gravity, it could last forever. However, humans wouldn't be able to see it. By about two trillion years from now, all of the galaxies beyond our local supercluster will be so far away that we can't see them: beyond the cosmic horizon. Should dark matter supersede gravity, causing the universe's expansion rate to increase further, it would hasten that two-trillion-year timeline. If, on the other hand, gravity were to prevail over dark energy, everything that has expanded into the universe as we know it would someday fall back into itself in a "Big Crunch." Happily, we've got enough time to find out.
Yahoo
25-04-2025
- Science
- Yahoo
Hubble Space Telescope's 35th anniversary: See NASA's new out-of-this-world images
During its 35 years of orbiting the Earth, the Hubble Space Telescope has transmitted endless streams of magnificent images, confirmed the existence of "dark matter," and helped track a vagabond black hole moving through the Milky Way. To celebrate the Hubble telescope's 35th anniversary, NASA released some striking new images on Wednesday, including a bold rendition of Mars and a stunning photo of a moth-shaped nebula with a white dwarf star in the middle. Built by Lockheed Martin in Sunnyvale, California, the Hubble Space Telescope was launched on the space shuttle Discovery from Kennedy Space Center in Florida on April 24, 1990. Since it orbits above the Earth, it can capture better cosmic images than telescopes on the ground. Hubble has made more than 1.6 million observations over the course of its lifetime, NASA says. And Hubble's discoveries have spawned more than 21,000 peer-reviewed science papers. The James Webb Space Telescope, which orbits the sun, has captured much space news attention, but it certainly hasn't put Hubble out of business. The Hubble telescope was designed to be the first space-based observatory, which could be serviced and upgraded while it remained in orbit. It was named after Edwin Hubble, the astronomer who showed that other galaxies existed beyond our own and came up with a classification scheme distinguishing galaxies by shape. About the same size as a school bus, the Hubble telescope uses three types of instruments to capture images across the universe: Cameras: Hubble has two cameras – the Advanced Camera for Surveys (ACS), which is primarily used for visible-light imaging, according to NASA. The Wide Field Camera 3 (WFC3) views infrared and ultraviolet wavelengths for higher resolution, deeper images. The ACS was repaired and the WFC3 was installed during a May 2009 servicing mission involving five spacewalks by astronauts from the space shuttle Atlantis. Spectrographs: The Cosmic Origins Spectrograph is the most sensitive ultraviolet spectrograph ever, capturing light and breaking it down to assess temperature, density, chemical composition, and velocity of objects, such as stars and quasars. The Space Telescope Imaging Spectrograph, also repaired in 2009, captures many forms of light, including ultraviolet to near-infrared light. Interferometers: The telescope has three Fine Guidance Sensors used to target and measure the relative positions and brightness of stars. Mike Snider is a reporter on USA TODAY's Trending team. You can follow him on Threads, Bluesky, X and email him at mikegsnider & @ & @mikesnider & msnider@ What's everyone talking about? Sign up for our trending newsletter to get the latest news of the day This article originally appeared on USA TODAY: Hubble Space Telescope 35th anniversary: See NASA's new images
