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Milky Way’s neighbouring galaxy is of same size, not bigger

With Andromeda no longer considered the Milky Way's big brother

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UFO religion as a concept is now becoming a part of popular understanding.
Countless galaxies exist in the universe, each hiding secrets that humankind is yet to unearth. Pixabay
  • Astronomers discover that the other galaxy nearest to us is the same size as ours
  • The name of the other galaxy is Andromeda
  • It is heavier than sun but the same size as Milky Way

In what could put a galactic arms race to rest, astronomers have discovered that our nearest big neighbour, the Andromeda galaxy, is roughly the same size as the Milky Way.

It had been thought that Andromeda was two to three times the size of the Milky Way, and that our own galaxy would ultimately be engulfed by our bigger neighbour.

Galaxy nearest to Milky Way is not larger than it. VOA
Galaxy nearest to Milky Way is not larger than it. VOA

But the new study, published in the journal Monthly Notices of the Royal Astronomical Society, evens the score between the two galaxies.

It found the weight of the Andromeda is 800 billion times heavier than the Sun, on par with the Milky Way.

The research suggests scientists previously overestimated the amount of dark matter in the Andromeda galaxy.

Also Read: Planets Beyond Milky Way Galaxy Discovered For First Time

“We had thought there was one biggest galaxy and our own Milky Way was slightly smaller but that scenario has now completely changed,” said Prajwal Kafle from the University of Western Australia.

“By examining the orbits of high speed stars, we discovered that this galaxy has far less dark matter than previously thought, and only a third of that uncovered in previous observations,” he said.

Andromeda  is heavier than sun. VOA
Andromeda is heavier than sun. VOA

The study used a new technique to measure the speed required to escape a galaxy.

“When a rocket is launched into space, it is thrown out with a speed of 11 km per second to overcome the Earth’s gravitational pull,” he said.

“Our home galaxy, the Milky Way, is over a trillion times heavier than our tiny planet Earth so to escape its gravitational pull we have to launch with a speed of 550km/s,” Kafle said.

Andromeda is same size as the Milky way galaxy. Wikimedia Commons
Andromeda is same size as the Milky way galaxy. Wikimedia Commons

“We used this technique to tie down the mass of Andromeda,” he added.

The Milky Way and Andromeda are two giant spiral galaxies in our local Universe, and light takes a cosmologically tiny two million years to get between them.

With Andromeda no longer considered the Milky Way’s big brother, new simulations are needed to find out what will happen when the two galaxies eventually collide, suggests the study.

Next Story

U.S. To Roll Out New Strategy For Space Based Missile Defense

The release of the strategy was postponed last year for unexplained reasons, though it came as Trump was trying to persuade North Korea to give up its nuclear weapons.

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USA, Space, missile
This photo shows the launch of the U.S. military's land-based Aegis missile defense testing system, that later intercepted an intermediate range ballistic missile, from the Pacific Missile Range Facility on the island of Kauai in Hawaii, Dec. 10, 2018. VOA

The Trump administration will roll out a new strategy for a more aggressive space-based missile defense system to protect against existing threats from North Korea and Iran and counter advanced weapon systems being developed by Russia and China.

Details about the administration’s Missile Defense Review — the first compiled since 2010 — are expected to be released during President Donald Trump’s visit to the Pentagon with top members of his administration.

The new review concludes that in order to adequately protect America, the Pentagon must expand defense technologies in space and use those systems to more quickly detect, track and ultimately defeat incoming missiles.

Recognizing the potential concerns surrounding any perceived weaponization of space, the strategy pushes for studies. No testing is mandated, and no final decisions have been made.

Russia, missile
Photo made from footage taken from Russian Defense Ministry official web site on March 11, 2018 shows the Kinzhal hypersonic missile flying during a test in southern Russia. VOA

Missile sensors in space

Specifically, the U.S. is looking at putting a layer of sensors in space to more quickly detect enemy missiles when they are launched, according to a senior administration official, who briefed reporters Wednesday. The U.S. sees space as a critical area for advanced, next-generation capabilities to stay ahead of the threats, said the official, who spoke on condition of anonymity to disclose details of the review before it was released.

The administration also plans to study the idea of basing interceptors in space, so the U.S. can strike incoming enemy missiles during the first minutes of flight when the booster engines are still burning.

Congress, which ordered this review, has directed the Pentagon to push harder on this “boost-phase” approach, but officials want to study the feasibility of the idea and explore ways it could be done.

The new strategy is aimed at better defending the U.S. against potential adversaries, such as Russia and China, who have been developing and fielding a much more expansive range of advanced offensive missiles that could threaten America and its allies. The threat is not only coming from traditional cruise and ballistic missiles, but also from hypersonic weapons.

For example, Russian President Vladimir Putin unveiled new strategic weapons he claims can’t be intercepted. One is a hypersonic glide vehicle, which could fly 20 times faster than the speed of sound and make sharp maneuvers to avoid being detected by missile defense systems.

USA, missile
This image made from video of a news bulletin aired by North Korea’s KRT on May 15, 2017, shows what was said to be the launch of the Hwasong-12 missile at an undisclosed location in North Korea VOA

“Developments in hypersonic propulsion will revolutionize warfare by providing the ability to strike targets more quickly, at greater distances, and with greater firepower,” Lt. Gen. Robert Ashley, director of the Defense Intelligence Agency, told Congress last year. “China is also developing increasingly sophisticated ballistic missile warheads and hypersonic glide vehicles in an attempt to counter ballistic missile defense systems.”

Command

Current U.S. missile defense weapons are based on land and aboard ships. Trump and Vice President Mike Pence have both emphasized space-based capabilities as the next step of missile defense.

Senior administration officials earlier signaled their interest in developing and deploying more effective means of detecting and tracking missiles with a constellation of satellites in space that can, for example, use advanced sensors to follow the full path of a hostile missile so that an anti-missile weapon can be directed into its flight path.

Implications for diplomacy

Any expansion of the scope and cost of missile defenses would compete with other defense priorities, including the billions of extra dollars the Trump administration has committed to spending on a new generation of nuclear weapons. An expansion also would have important implications for American diplomacy, given long-standing Russian hostility to even the most rudimentary U.S. missile defenses and China’s worry that longer-range U.S. missile defenses in Asia could undermine Chinese national security.

Trump
President Donald Trump talks with reporters on the South Lawn of the White House before departing for the American Farm Bureau Federation’s 100th Annual Convention in New Orleans, Jan. 14, 2019, in Washington. VOA

Asked about the implications for Trump’s efforts to improve relations with Russia and strike better trade relations with China, the administration official said that the U.S. defense capabilities are purely defensive and that the U.S. has been very upfront with Moscow and Beijing about its missile defense posture.

Also Read: SpaceX Drops Plan To Make its Falcon 9 Even More Reusable

The release of the strategy was postponed last year for unexplained reasons, though it came as Trump was trying to persuade North Korea to give up its nuclear weapons.

While the U.S. continues to pursue peace with North Korea, Pyongyang has made threats of nuclear missile attacks against the U.S. and its allies in the past and has worked to improve its ballistic missile technology. It is still considered a serious threat to America. Iran, meanwhile, has continued to develop more sophisticated ballistic missiles, increasing their numbers and their capabilities. (VOA)