When you want to see the stars, find someplace dark
Today Mercury will be at maximum western elongation, as high in the morning sky as it will appear for this current apparition. After today the planet will slide back into the dawn, passing through superior conjunction on October 8th to reappear in the evening sky around the end of the month.
There are no transits of Mercury in 2017, the next will be Nov 11, 2019.
Today the planet Neptune will pass through opposition, directly opposite the Sun in our sky. The planet will be well placed for observation all night long, rising at sunset, transiting at midnight, and setting at sunrise. If you are looking to observe Neptune, it is currently shining at magnitude 7.8 in the center of the constellation Aquarius.
As the outer planets Uranus and Neptune move so slowly across the sky, the timing of oppositions is driven by the Earth’s orbit and occur each year at nearly the same time. Neptune’s orbital period is 164.8 years, taking over a century and a half to circle the celestial globe once. As Neptune was discovered in 1846, it has completed a little over one orbit since discovery.
Today Mercury will be at inferior conjunction. After today the planet will reappear in the dawn, rising high enough from the Sun’s glow to be seen in mid September.
Today Mercury will be at maximum eastern elongation, as high in the evening sky as it will appear for this current apparition. After today the planet will slide back into the sunset, passing through inferior conjunction on August 26th to reappear in the morning sky in mid-September.
There are no transits of Mercury in 2017, the next will be Nov 11, 2019.
Today Mercury will be at superior conjunction. After today the planet will reappear in the evening sky, rising high enough from the Sun’s glow to be seen early next month.
As Mercury is on an orbit inside that of Earth’s it will see both inferior and superior conjunctions as it passes from the evening sky to the dawn sky and back again.
Today the planet Saturn will pass through opposition, directly opposite the Sun in our sky.
During opposition the planet and rings will be slightly brighter than normal, an effect known as the opposition effect. The effect is most notable in the rings where the apparent brightness can increase by 30%. The effect is a combination of two factors, shadow hiding and the retro-reflective properties of the ring particles.
Today Venus is at maximum elongation, as high in the dawn sky as it will get for this morning apparition, about 45.9°. After today the planet will begin its slide back into the glare of dawn. It will disappear from view around the end of the year and reach superior conjunction on January 8th, 2018.
As Earth and Venus race about the Sun, Venus will complete about one cycle of appearances each year. We can expect one evening apparition and one morning apparition to occur in 2017.
Today Mercury will be at maximum western elongation, as high in the morning sky as it will appear for this current apparition. After today the planet will slide back into the dawn, passing through superior conjunction on June 21st to reappear in the evening in mid-July.
There are no transits of Mercury in 2017, the next will be Nov 11, 2019.
Today Mercury will be at inferior conjunction. After today the planet will reappear in the dawn, rising high enough from the Sun’s glow to be seen around the end of the month.
Jupiter will pass through opposition at 10:58HST today.
Look for a bright object rising in the eastern sky after sunset. It is difficult to mistake for anything else, shining at it’s brightest during opposition, a brilliant -2.7 magnitude. For the remainder of the spring and much of the summer, the planet will be quite prominent in the evening sky.