Lonar
A crater lake in volcanic rock, sacred and ancient.
Key facts
- When
- about 570,000 years ago
- Where
- Buldhana district, Maharashtra, India
- What hit
- an asteroid perhaps 50 to 100 m across
- Era
- In the age of humans
- Location
- 19.98° N, 76.51° E
Very roughly a few tens of megatons of TNT, judging by the crater's size.
Comparable to the largest hydrogen bombs ever tested.
What happened
Lonar is a nearly circular crater about 1.8 km across, holding a salty, alkaline lake. It was blasted into the Deccan Traps, layer upon layer of basalt lava that erupted around 66 million years ago. That makes Lonar a rare example on Earth of a crater in basalt, the same kind of rock that covers the dark plains of the Moon and much of Mars.
Its age has been revised several times. Older estimates of about 50,000 years have given way to a date of about 570,000 years from more recent dating of melted rock.
Temples, some more than a thousand years old, stand around the rim and in the crater, and the lake has long been a place of pilgrimage.
Effects
Ejecta and melted rock were thrown around the crater; the lake today supports unusual microbes adapted to its alkaline water. In 2020 the lake water briefly turned pink, a change caused by salt-loving microbes when the water level dropped.
The evidence
Shocked basalt in which the feldspar has been turned to glass, called maskelynite, along with impact melt and spherules.
Did you know?
Lonar was confirmed as an impact crater in the 1970s.
Because it formed in basalt, scientists compare Lonar with craters on Mars and the Moon.
Related pages
How is impact energy measured? See energy explained, or try the impact calculator.