The molten rock rising inside Mount St. Helens (search) is giving the peak an eerie red glow at night.

Lava has been climbing to the surface at nearly 1,300 degrees for the past few days in a process that scientists said Wednesday could go on for days, weeks or months. At night, low-hanging clouds and the steam rising from the volcano reflect the glow of the red-hot stone inside the crater.

Scientists said they do not know how long the eruption might continue, or whether it will be marked by explosive blasts. But they said any eruption would probably be far less dangerous than the cataclysmic explosion in 1980 that blasted away much of the mountaintop and killed 57 people.

The area immediately around the mountain remains closed.

The molten rock, or magma, rising inside the mountain has been depositing itself on the crater floor inside the volcano, halfway up the 8,634-foot peak, creating a "fin" of rock estimated Tuesday at 60 to 90 feet tall and 150 to 180 feet wide.

The fin, at about 750 degrees, has a pinkish cast "like medium roast beef," geologist Tina Neal of the U.S. Geological Survey (search) said.

The glowing rock itself can be seen only from above, from aircraft.

Lava first reached the surface on Monday, following 2 1/2 weeks of rumblings and steam and ash bursts from the mountain.