Author: Astronomy & Astrophysics

I was wondering if you could go in depth, at l…

I was wondering if you could go in depth, at least to a degree about how incredibly dense objects have strong enough gravity to distort light. To me that's one of the wildest concepts I can imagine, not that I expect you to be all knowing but maybe you've got a good article or something? I don't recall if you've ever made posts about the theory of relativity. Sorry for the long ask!

Well, I know only the basics, things I study in my free time, however, I can try to explain. The distortion of space-time is described by Einstein’s Theory of General Reality. The more massive an object, the more its curvature will be in the space-time fabric.

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This distortion in light is known as a gravitational lensing. The gravitational lensing is formed due to a space-time distortion caused by the presence of a large mass body between a distant light source and an observer.

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These distortions are widely observed through globular clusters.

Since the amount of lensing depends on the total mass of the cluster, gravitational lensing can be used to ‘weigh’ clusters. This has considerably improved our understanding of the distribution of the ‘hidden’ dark matter in galaxy clusters and hence in the Universe as a whole. The effect of gravitational lensing also allowed a first step towards revealing the mystery of the dark energy.

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As gravitational lenses function as magnification glasses it is possible to use them to study distant galaxies from the early Universe, which otherwise would be impossible to see.

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Gravitational lensing happens on all scales – the gravitational field of galaxies and clusters of galaxies can lens light, but so can smaller objects such as stars and planets. Even the mass of our own bodies will lens light passing near us a tiny bit, although the effect is too small to ever measure.

What would cause two stars to collide? What do…

What would cause two stars to collide? What does it take for a whole planet (as massive as Jupiter) to change trajectory?

The main mechanism that would make two stars collide is gravity. This depends on several factors, some stars may wander through space and end up being attracted by the gravitational field of another star, from there, one star begins to orbit the other. 

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But the most common are collisions in clusters of stars, because in a star cluster the stars are very close together, especially in globular clusters. 

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Collisions of young stars may also occur, as most of the stars are born close to each other in clusters. Many stars are binary, formed together, but in some cases before they evolve they may end up colliding.

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In the universe both collisions of active stars can occur, as can collisions of white dwarfs, neutron stars and black holes.

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The orbits of the planets are determined by the gravitational pull of the Sun, so it would need some very extreme force to cause the orbit of a planet to change its trajectory, perhaps if some planet or star enters our solar system, or when the Sun goes through changes and become a white dwarf in about 5 billion years.

What do you think about scientific facts which…

What do you think about scientific facts which are mentioned in Qura’n (the holy book of islam)

I never read the Quran

A view of the Space Shuttle Atlantis departi…

A view of the Space Shuttle Atlantis departing the Mir Russian Space Station. This image was taken during the STS-71 mission by cosmonauts aboard their Soyuz TM transport vehicle.

How were black holes discovered?

How were black holes discovered?

The idea of a massive body from which nothing can escape was first formed by geologist John Michell. The first modern solution to general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916.

 However the first object considered a black hole is the Cygnus X-1. more

Cygnus X-1 was the subject of a 1974 friendly wager between Stephen Hawking and a fellow physicist Kip Thorne, with Hawking betting that the source was not a black hole. In 1990, he conceded defeat.

Supermassive Black hole

Donald Lynden-Bell and Martin Rees hypothesized in 1971 that the center of the Milky Way galaxy would contain a supermassive black hole. Sagittarius A* was discovered and named on February 13 and 15, 1974, by astronomers Bruce Balick and Robert Brown using the Green Bank Interferometer of the National Radio Astronomy Observatory. They discovered a radio source that emits synchrotron radiation; it was found to be dense and immobile because of its gravitation. This was, therefore, the first indication that a supermassive black hole exists in the center of the Milky Way.

The very energetic radiation from young hot …

The very energetic radiation from young hot stars in the star cluster NGC 3603 is bursting into colder gas and dust making the gas glow. The radiation from the stars has blown a ‘bubble’ around the cluster free from gas.

Credit: Wolfgang Brandner (JPL/IPAC), Eva K. Grebel (Univ. Washington), You-Hua Chu (Univ. Illinois Urbana-Champaign), and NASA/ESA

In Conversation with the Sun: Parker Solar Pro…

nasa:

Our Sun powers life on Earth. It defines our days, nourishes our
crops and even fuels our electrical grids. In our pursuit of knowledge
about the universe, we’ve learned so much about the Sun, but in many ways we’re
still in conversation with it, curious about its mysteries.

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Parker Solar
Probe
will advance this conversation, flying
through the Sun’s atmosphere as close as 3.8 million miles from our star’s
surface, more than seven times closer to it than any previous spacecraft. If
space were a football field, with Earth at one end and the Sun at the other,
Parker would be at the four-yard line, just steps away from the Sun! This
journey will revolutionize our understanding of the Sun, its surface and solar
winds.

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Supporting Parker on its journey to the
Sun are our communications networks. Three networks, the Near Earth Network,
the Space
Network
and the Deep Space Network, provide our
spacecraft with their communications, delivering their data to mission
operations centers. Their services ensure that missions like Parker have
communications support from launch through the mission.

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For Parker’s launch
on Aug. 12, the Delta IV Heavy rocket that sent Parker skyward relied on the Space
Network. A team at Goddard Space Flight Center’s Networks Integration Center
monitored the launch, ensuring that we maintained tracking and communications
data between the rocket and the ground. This data is vital, allowing engineers
to make certain that Parker stays on the right path towards its orbit around
the Sun.

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The Space Network’s constellation of Tracking and Data
Relay Satellites
(TDRS) enabled constant communications coverage for
the rocket as Parker made its way out of Earth’s atmosphere. These satellites
fly in geosynchronous orbit, circling Earth in step with its rotation, relaying
data from spacecraft at lower altitudes to the ground. The network’s three collections
of TDRS over the Atlantic, Pacific and Indian oceans provide enough coverage
for continuous communications for satellites in low-Earth orbit.

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The Near Earth Network’s Launch
Communications Segment tracked early stages of Parker’s launch, testing our brand
new ground stations’ ability to provide crucial information about the rocket’s
initial velocity (speed) and trajectory (path). When fully operational, it will
support launches from the Kennedy spaceport, including upcoming Orion
missions. The Launch Communications Segment’s three ground stations are located
at Kennedy Space Center; Ponce De Leon, Florida; and Bermuda. 

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When Parker separated from the Delta IV
Heavy, the Deep Space Network took over. Antennas up to 230 feet in diameter at
ground stations in California, Australia and Spain are supporting Parker for
its 24 orbits around the Sun and the seven Venus flybys that gradually shrink
its orbit, bringing it closer and closer to the Sun. The Deep Space Network is
delivering data to mission operations centers and will continue to do so as
long as Parker is operational.

Near the
Sun, radio interference and the heat load on the spacecraft’s antenna makes
communicating with Parker a challenge that we must plan for. Parker has three
distinct communications phases, each corresponding to a different part of its
orbit.

When Parker comes closest to the Sun, the
spacecraft will emit a beacon tone that tells engineers on the ground about its
health and status, but there will be very little opportunity to command the
spacecraft and downlink data. High data rate transmission will only occur
during a portion of Parker’s orbit, far from the Sun. The rest of the time,
Parker will be in cruise mode, taking measurements and being commanded through
a low data rate connection with Earth.

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Communications infrastructure is vital to
any mission. As Parker journeys ever closer to the center of our solar system,
each byte of downlinked data will provide new insight into our Sun. It’s a
mission that continues a conversation between us and our star that has lasted many
millions of years and will continue for many millions more.

For more information about NASA’s mission
to touch the Sun: https://www.nasa.gov/content/goddard/parker-solar-probe

For more information about our satellite
communications check out: http://nasa.gov/SCaN


Make sure to follow us on Tumblr for your regular dose of space: http://nasa.tumblr.com.

Hey, i really love your blog and i was wonderi…

Hey, i really love your blog and i was wondering what do you study ? or "did study"

Thank you. I just studied at home and read some books.

Are astrology and conciousness related?

Are astrology and conciousness related?

In astrology much is spoken of in superstition, unlike science that is a field where one studies, researches or investigates something to complete the final result, that is, science is made of facts. But honestly I have never studied or researched aboult astrology, so I prefer not to comment on it, consciousness is quite quoted in quantum physics, although many physicists do not like to involve the action of consciousness and quantum physics.

Images of the Earth and the moon above the Rin…

Images of the Earth and the moon above the Rings of Saturn taken by Cassini on April 13, 2017.

Credit:

NASA/JPL-Caltech/SSI/CICLOPS/Kevin M. Gill