Astronomers are eagerly awaiting tonight, when Jupiter makes its closest approach to Earth in 59 years – an event known as planetary opposition.
This asteroid may be smaller than many that have gained headlines, yet it comes much closer to Earth than those which remain thousands of miles away.
Earth
Earth is the sole planet where life has ever arisen, providing the ideal conditions for its existence. From its proximity to the sun and availability of water and essential chemicals, to volcanism and geological activity which oxygenate its atmosphere and generate a sustainable lifecycle – Earth offers everything necessary for its existence and furthermore benefits from protection provided by its magnetic field and low mass. All these factors have led to its rapid evolution over billions of years!
Earth offers exceptional conditions for human life due to its geological history and vast ocean. This combination makes Earth an excellent location for interstellar exploration.
Some asteroids and comets travel on orbital paths that bring them close to Earth compared to their usual orbits, making near-Earth objects easily visible with telescopes. Astronomers refer to such objects as near-Earth objects; there have been instances when they came close enough for observers to spot. Although there is no risk that they would collide with our planet, near-Earth objects should be seen with proper care as potential near-Earth objects can pass close enough that telescope observations warrant being made of them.
NASA’s Asteroid Watch dashboard reports that five asteroids, including one house-sized and two the size of airplanes, will fly past Earth between Sept 6-12 according to their path. Of the five asteroids JA5 will come closest, coming within 3.17 million miles – so its name was coined after all! At about 59 feet wide in diameter it has even been likened to being likened to a house!
On May 6, Jupiter will appear larger and brighter than usual when it crosses across the face of the sun in what is known as a planetary opposition – one of only eight times ever when all eight planets in our solar system can align along an imaginary line in the sky.
Researchers using the MEarth-South array of 8 40cm robotic telescopes at Cerro Tololo Inter-American Observatory in Chile have recently identified WASP-76b – only 1.83 times larger than Jupiter but 0.92 times more massive – orbiting a young star 100 light years away from Earth. Scientists believe WASP-76 b is tidally locked – meaning one side faces towards its host star while the other turns inward towards space – potentially providing insights into processes behind planet formation similar to our own planet!
Venus
Venus has long been one of the celestial highlights, readily visible after sunset if one gazes westward after sundown. Now however, the second rock from the sun is undergoing a transformation visible to anyone willing to take notice: Its approach inferior conjunction, when Venus will pass directly between Sun and Earth for five-and-a-half months at a time; during which Venus will gradually sink downward from view before eventually dissipating entirely every 584 days.
Venus’ brightness can be bewildering; its glare nearly blinding. Venus is twice as bright as our Moon and was widely revered during ancient times as both morning and evening star, inspiring poets such as Homer and Virgil as well as science fiction writers like Edgar Rice Burroughs (“Pirates of Venus,” 1934) and Arthur C. Clarke (“Before Eden,” 1961).
Venus will appear for several months after sunset in the western sky and before dawn in the eastern dawn sky, before finally joining Jupiter in the evening sky on March 1. Their proximity will offer an excellent opportunity to view both, since Jupiter will soon disappear into twilight glare while Venus remains visible longer than any other planet during March.
Venus is the hottest planet in our Solar System and boasts an atmosphere 90 times thicker than that of Earth, making it an energy hog and driving global warming through greenhouse effects. Unfortunately, however, Venus lacks plate tectonics preventing scientists from understanding much about its internal structure.
Since the 1960s, space probes have been sent into orbit and onto Venus in an effort to gain further insights into what might lie below its surface. Data from these missions quickly disproved any notion that Venus was any different from our own planet’s and has since become one of our best models for understanding climate change in our own environment.
Mars
Every 26 months, Mars and Earth come together in a cosmic dance known as a close approach, giving amateur astronomers and scientists alike a rare chance to observe our charming neighbor through telescopes. Additionally, scientists gain an opportunity to gain a greater insight into its past and future development.
Mars shines much brighter during close approaches due to being in opposition with the Sun; when this alignment takes place only once every two years, Mars becomes much brighter than usual.
Astronomers are taking advantage of this phenomenon to study Mars and its two small moons, Phobos and Deimos. In their quest to understand why the Red Planet ticks so reliably, astronomers hope to use shorter journey times as an excuse to send more spacecraft there.
Mars will come close to Earth this month by approximately one billion miles, yet still be 191 million miles closer than normal and appear 85 times brighter than normal – possibly outshimmering Venus – currently the third brightest object in our night sky.
NASA estimates that this will be the final close approach of Mars to Earth for more than 60,000 years – it will next appear close by in 2035.
At nightfall, Mars will appear as a reddish glow in the southeast sky and reach its maximum brightness around early evening. At this time it is traveling in front of Capricornus, the Sea-goat constellation.
Observers should keep in mind that Mars can fluctuate quickly from night to night, and should wait and try again if they don’t see it at first sight. Mars will also be visible early morning sky in Taurus constellation despite being lower than usual.
On July 15 morning, Mars (mag 0.9) will pass very close to Neptune (mag 5.7), providing a dramatic sight that’s best observed with binoculars but should also be easily visible with naked eyes.
Mercury
Mercury is both Earth’s closest neighbor and closest planet in our Solar System overall, but Venus actually outdistances Mercury as far as average distance goes! That’s because planets in Venus’ orbit spend more time on the opposite side of the Sun from us here on Earth than does Mars; scientists at NASA, Los Alamos National Laboratory and U.S. Army came up with a model called PCM to explain this disparity; using math it measures average distances between planets that share concentric and coplanar orbits as well as share an eccentricity parameter between two concentric and circular orbits sharing coplanar orbital planes (ie sharing an orbital plane), coplanar orbits (sharing an orbital plane), coplanarity orbiting around a common orbital plane), circular orbits and shared eccentricities (ie an eccentricity factor between two orbital planes), coplanar (ie orbits), coplanar coplanarity and eccentricity between their respective orbital planes/es respectively based on sharing an eccentricity factor between two planets (based on how math determines “point circle method”) to calculate average distance between two planets sharing concentric, coplanar (ie having the same orbital plane), circular orbital plane/circles and share an eccentricity factor).
The PCM model shows that, on average, Mercury is closer to Earth than Venus is and even closer than all the inner Solar System planets (such as Mars and Pluto! ).
Mercury doesn’t possess natural satellites like the Moon does; however, it does possess a thin atmosphere composed of hydrogen and helium and has a magnetic field weaker than our own yet still strong enough to deflect solar wind away from its surface.
Mercury orbits close to the Sun on an elliptical path, coming close at times when its inferior conjunction occurs, as evidenced by this GIF from Reddit user u/CharcoalCharts. At these moments, its path seems to turn inward toward Mercury in the sky; at that moment the Sun seems to reverse itself and begin moving in that direction again. At that time, its intense heat warms its equatorial regions known as hot poles on Mercury.
NASA’s Mariner 10 spacecraft visited Mercury three times during the 1970s, verifying its lack of moons but revealing an extremely thin atmosphere. Mariner 10 witnessed evidence of volcanic plains and wrinkle ridges across its surface but no permanent water ice formation. Furthermore, Mercury has an extreme axial tilt so one side always faces towards the Sun while the other turns away from it.
Due to this planetary alignment, Mercury can be seen through a telescope at its greatest elongation around January 12 – when its magnitude will increase from 0.50 to 0.75 and span 7.5 arcseconds across.