Neptune will appear in the earth’s sky before dawn tomorrow (Tuesday) as the planet completes its 164.7-year orbit around the sun for the first time since it was discovered in 1846, the weather bureau has said.
It will be the first time Neptune will be visible to modern earthlings but, unfortunately, the rainy weather may make it difficult to view.
The Philippine Atmospheric, Geophysical and Astronomical Services Administration’s (Pagasa) observatory said it would be unlikely for stargazers to see Neptune’s rendezvous with the constellations of Aquarius and Pisces at 1 a.m. Tuesday.
Even in clear skies, Neptune—the farthest from Earth since Pluto lost its planet status in 2006— may be seen glowing faintly in the east-southeast horizon only with a telescope or binoculars.
Uranus will also appear in the sky.
“Binoculars or a telescope will be needed to view both these planets,” Pagasa said.
Icy Neptune was discovered on Sept. 23, 1846, and is only completing its orbit around the sun this year, some 164.79 earth years since it was first detected by astronomers and mathematicians.
Earthlings did not actually see Neptune until 1989, when the US probe Voyager passed by the planet and took photographs.
Jupiter will appear brightly (visible to the naked eye) on the eastern horizon, “among the background stars of the constellation Aries.” Its four moons can be seen changing positions as they orbit their mother planet, Pagasa said.
Venus will also be visible before sunrise in the east northeastern horizon until the first half of July, while Mars may be seen at dawn throughout the month, the weather bureau added.
The planets Saturn and Mercury will show up in the evening sky in the western horizon just before sunset, it said.