Lake Janisjarvi
Credit: NASA, Posted on: Thursday, 1 May 2008, 07:11 CDT Download full size image
Lake Jänisjärvi is a roughly oval-shaped lake, some 13 by 17 kilometers (8 by 11 miles) across, in northwestern Russia, near the Finnish border. The basin for this lake was formed hundreds of millions of years ago by a meteorite impact.
On September 5, 1999, NASA’s Landsat-7 satellite captured this image of Lake Jänisjärvi and its surroundings. This late-summer shot shows a lush green landscape free of snow and ice. Land around the lake appears in varying shades of green, interrupted by tan and pink swaths of cleared (probably agricultural) land, particularly in the east. The lake itself is deep blue, dotted with diminutive islands. A close look at the lake’s ragged contours indicates that the this water body is connected to many others in the area. The tiny tributary exiting this lake’s southern edge meanders toward Lake Ladoga to the south.
Underneath the vegetation, rocks hold clues about Lake Jänisjärvi’s past. Rocks modified by a meteor impact, known as impactites form a sheet over the area. These rocks are especially prominent in the tiny islands in the center of the lake, and along the southeast part of the shoreline. Geologists suspect that Pleistocene glaciers carried the rocks along the lake’s southeastern shore to their current location. The crater itself, however, is estimated to be much older than the Pleistocene; its age is estimated at roughly 700 million years old, making it older than the first mammals, dinosaurs, and even fish.
More Images

Microscope Image of a Martian Soil Surface Sample.This is the closest view of the material underneath NASA's Phoenix Mars Lander. ...

Youthful Wrinkles.During a distant flyby encounter with Enceladus, Cassini imaged the moon's wrinkled leading hemisphe...
Recent Images
- Youthful Wrinkles
- Microscope Image of a Martian Soil Surface Sample
- Dust Plume off Iceland
- NASA Spacecraft Finds the Sun is Not a Perfect Sphere
- Merging Lobate Debris Aprons of Deuteronilus Mensae
- Roan Plateau, Colorado
- Hubble Image of NGC 3324
- Unconformity in North Polar Layered Deposits
- Earth from Space: Western Europe
Latest Thoughts
A Workout for the Eyes
The Heart Beats On
War Veterans Going Blind
Invisible Hearing Aids
Horseback Therapy Helps Kids Defy All Odds
New Drug Saves Eyesight













RSS Feeds