At a penumbral eclipse the Moon passes only through the outer, lighter part of the Earth’s shadow, the penumbra, and never touches the dark inner shadow. The Moon is not bitten and does not turn red. It grows a little dimmer, and near the greatest eclipse the side nearest the shadow’s centre looks faintly smoky, as if it had been smudged. It is easy to miss unless you know when to look, and a photograph taken through the eclipse shows the change better than the eye. With a penumbral magnitude of 0.927, this is a fairly deep penumbral eclipse, and the shading at the greatest moment is visible to anyone who looks for it.
Times and visibility
The Moon enters the penumbra at 21:12 UT on 20 February, is deepest at 23:12 UT, and leaves it at 01:13 UT on the 21st. Everyone who has the Moon above the horizon in those hours sees it. In India that is the whole of the night: in New Delhi and Mumbai the penumbra begins at 02:42 on the morning of 21 February, is deepest at 04:42, and ends at 06:43. In London the eclipse begins at 21:12 on the 20th, reaches its greatest at 23:12 and ends at 01:13. In New York the Moon rises at 17:31 with the eclipse already under way, and the greatest eclipse comes at 18:12, so you can watch the whole second half. Perth sees the beginning before the Moon sets at 05:58, but not the greatest eclipse.
Is it a grahan?
Most Hindu almanacs do not count a penumbral eclipse as a grahan. The Moon’s disc is not visibly eaten by the shadow, and the tradition counts an eclipse from the moment the Moon is touched by the dark shadow, the umbra. For that reason many Indian panchangs give no sutak for this eclipse and expect no special observances. The table’s sutak column therefore reads None. A family that keeps its own rule may still choose to chant or rest, and that is a personal choice.
In the Hindu calendar
The date is Magha Purnima, the full moon of Magha, a day on which many people bathe at rivers and sacred places and give to the poor. The Moon at the greatest eclipse is in Simha, the sidereal Leo, at 7.8 degrees, in Magha nakshatra, and the Sun is opposite, in Kumbha. Magha is the nakshatra that gives the month its name. Those are Lahiri positions worked out to within a few hundredths of a degree. The ordinary Purnima observances, for which the Purnima page has the tithi times, do not change because of the eclipse.
How to watch
Go outside a little before the greatest eclipse, 04:42 in India, and let your eyes adjust to the dark for ten minutes. Compare the left and right sides of the Moon, and the Moon with how it looked an hour earlier. Photographs taken with the same settings an hour before and at the greatest eclipse show the difference clearly. It is safe to look at with the naked eye, binoculars or a telescope.