Black Moon on 19 August: Invisible fourth 'New Moon' in Northern Hemisphere appears due to calendar quirk
A second full moon in a single calendar month is a Blue Moon, and the flip side of this phenomenon, a Black Moon.


The Black Moon will be more or less invisible, even if the moon is high in the sky. Image Credit: Te Papa[/caption]According to The Old Farmer's Almanac, a Black Moon is a term given to the third new moon in a season of four, when there are two new moons in the same month, or even when there are no new moons in a month. According to the website, "this could only happen in February, and thus is kind of rare, meaning once every 5 to 10 years."As per a report in Space.com, there are two definitions for Black Moon. Since the lunar calendar almost lines up with Earth's calendar, each month sees one full moon and one new moon. A second full moon in a single calendar month is also called a Blue Moon and by definition the flip side of it is a Black Moon.The report adds that at the 'new moon' phase the moon is always black and occurs when the moon passes through the same part of the sky as the sun and as such the moon's dark side faces the earth.However, sometimes the new moon passes directly between the Earth and the sun and people from Earth can see the moon's black silhouette crossing in front of the sun, causing a solar eclipse.

Careless Whispers: Scientists discover that plants can 'talk' to each other using smells
Life on Mars? European Space Agency’s Orbiter discovers ice water deposits at equator
Microsoft briefly overtakes Apple as the most valuable company, Apple back on top again
Even NASA is facing a tough time, starts layoffs following major budget cuts
ISRO, NASA's NISAR satellite to get ready by Jan-end, will monitor Earth's snow-covered regions
