Neptune to appear as faint light in sky early Tuesday

MANILA, Philippines—Neptune will appear in the sky as a faint light early Tuesday as the planet completes its orbit around the sun for the first time since its discovery in 1846, according to a bulletin of the government-run weather bureau.

But the rainy weather is expected to cast gloom over the sky show, which is supposed to be the first time the planet could be viewed in Earth’s sky.

The observatory of the Philippine Atmospheric, Geophysical and Astronomical Services Administration (Pagasa) said people would unlikely to see Neptune’s rendezvous with the Aquarius and Pisces constellations at 1 a.m. on Tuesday.

Even in clear skies, however, Neptune’s apparition could only be viewed via telescope and could not be seen with the naked eye because of its slight sparkle.

Pagasa’s astronomical diary said Neptune, the farthest from Earth since Pluto lost its planet status in 2006, could be seen at the east-southeast horizon, glowing faintly at +7.8 (heavenly bodies appear brighter as luminosity rating descends).

Uranus will also appear in the sky with a magnitude of +5.8.

“A binocular or a telescope will be needed to view these planets,” Pagasa said.

The icy planet 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, however, did not see Neptune until 1989, when US probe Voyager passed by the planet and took photographs.

Jupiter will, meanwhile, appear brightly at a magnitude -2.3 (visible to naked eye) on the eastern horizon, “among the background stars of the constellation Aries.” Its four moons could also be seen changing positions as they orbit its mother planet.

Venus will also be visible before sunrise in the east northeastern horizon until the first half of July, while Mars could also be seen at dawn throughout the month.

Planets Saturn and Mercury would, meanwhile, show up in the evening sky in the western horizon just before sunset, glowing at magnitudes of +0.9 and +0.3 (visible to naked eye) respectively.