“This space we declare to be infinite… In it are an infinity of worlds of the same kind as our own.”
Giordano Bruno (1584)
In the 16th century the Italian astronomer, mathematician, and philosopher, Giordano Bruno, became one of the first to propose that the stars we observe in our night sky are really fiery celestial objects similar to our Sun–and are likewise accompanied by their own retinue of planets. However, it was not until 1992 that the first batch of planets, circling a star beyond our own, were discovered–and they were genuine “oddballs” in orbit around a type of stellar corpse called a “pulsar”. Pulsars are very young neutron stars, the sad, dense, city-sized relics of massive stars that recently perished in the brilliant blast of a supernova explosion. The pulsar planets were the very first hint that planets existing in orbit around distant stars may be weird worlds that bear little or no resemblance to the planets inhabiting our own Solar System. In April 2017, astronomers announced that they had found yet another “oddball” distant world–another bizarre planet among the thousands of weird, wonderful, and sometimes eerily familiar worlds that have been discovered over the past generation. Sporting a mass similar to Earth, and orbiting its star at the same distance we orbit our Sun, it is a planetary “iceball”.
This bewitching world of ice is much too cold to be inhabited by life as we know it, because its parent-star is extremely faint. However, this discovery contributes to our scientific understanding of the often strange planetary systems that exist beyond our own Sun’s family.
“This ‘iceball’ planet is the lowest-mass planet ever found through microlensing,” commented Dr. Yossi Shvartzvald in an April 26, 2017 NASA Jet Propulsion Laboratory Press Release. Dr. Shvartzvald is a NASA postdoctoral fellow based at the JPL, located in Pasadena, California, and lead author of a study published in the April 26, 2017 issue of the Astrophysical Journal Letters.
Magnifying Glasses In Space
Microlensing is a technique that aids in the detection of distant objects by using background stars as magnifying glasses. When a foreground star travels precisely in front of a brilliant background star, the gravity of the foreground star focuses the light emanating from the background star, making it appear brighter. If there is a planet orbiting the foreground star, it may cause an additional blip in its parent-star’s brightness. In the case of the “snowball” exoplanet, the blip only lasted for a few hours. Astronomers using this technique have discovered the most distant known exoplanets from Earth. Furthermore, this technique can spot low-mass planets that are considerably farther from their parent-stars than Earth is from the Sun.
The term gravitational lensing itself refers to the path that traveling light takes when it has been deflected. It occurs when the mass of a foreground object warps, bends, and distorts the light of an object situated in the background. The traveling light does not need to be entirely visible light–it an be any form of radiation. As a result of lensing, beams of traveling light that normally would not be seen are bent in such a way that their paths wander towards the observer. Conversely, beams of light can also be bent in such a way that they wander away from the observer. There are different types of gravitational lenses: strong lenses, weak lenses, and microlenses. The differences between these three distinct forms of gravitational lenses has to do with the position of the background object that is sending its light out into space, please visit:-https://www.orlo-matsuge.com/ https://imedenver.com/ the foreground lens that is distorting the light, and the position of the observer. The mass or shape of the foreground gravitational lens can also play an important role. Therefore, the foreground object determines how much light emanating from the background object will be distorted, and also where this light will wander.
Albert Einstein’s Theory of Special Relativity (1905), describes a Spacetime that is often compared to an artist’s blank canvas. The artist paints points and lines on this marvelous canvas which represents the stage where the universal drama is being played out–but it does not play a role in the drama itself. The great achievement linking the stage with the drama came a decade later with Einstein’s Theory of General Relativity (1915). According to General Relativity, Space itself becomes a star player in the drama. According to the play’s plot, Space tells mass how to move, and mass tells Space how to curve. Spacetime is as flexible as a trampoline, onto which children toss a heavy ball. The ball represents a massive object–for example, a star. The heavy ball creates a dimple in the flexible fabric of the trampoline. If the children then playfully toss marbles onto the stretchy fabric, the marbles will travel curved paths around the “star”–as if they were real planets in orbit around a real star. If the heavy ball is taken away, the marbles then travel straight paths on the fabric of the trampoline, because there is no dimple on the stretchy fabric to bend their paths. The stage and the drama are united, and it will last for as long as the main players exist.
The Theory of General Relativity predicts that heavy concentrations of mass in the Universe will warp traveling light like a lens, thus magnifying celestial objects situated behind the mass when observed by astronomers on Earth. The very first gravitational lens was detected back in 1979, and lensing now provides a new tool for astronomers to use in order to observe the Cosmos soon after its primordial birth about 14 billion years ago.
When the path that wandering light takes is far from the mass, or if the mass is not particularly large, weak lensing occurs–and the background object is only slightly distorted. In contrast, when the background object is positioned almost exactly behind the mass, strong gravitational lensing can occur, smearing out extended foreground objects–such as galaxies or galaxy clusters. However, the strong lensing of small, point-like objects often produces multiple images–such as an Einstein cross–dancing a dazzling display around the lens.
The idea that extrasolar planets exist has been contemplated for centuries. However, until about a generation ago, there was no way to detect them–or even to estimate how frequently they occur, or even to determine how similar (or dissimilar) they might be to the planets of our Sun’s familiar family.