Way too long ago. Try again.

The Earth hasn't been around that long,
nor our entire galaxy - the Milky Way.

Based on Hubble telescope images,
scientists estimate the Milky Way might be
12-13 billion years old.

The Sun and Earth are much younger
and formed about 4.5 billion years ago.

Too long ago.

There have been many ice ages since then.

Try Again.

Close, but still too long ago.
Over the last 1.5 million years, the northern hemisphere has been in a glacial mood with major cycles of glacial advance and retreat.

When did the latest glacial advance
cause this much ice cover?

You're right!

Did people take advantage of this situation to migrate from Asia to North America? As glaciers grew at the expense of water from the sea, shallow parts of the seafloor became exposed. Was there a time-window when people could have crossed, when it had warmed enough yet sea level was still low? Did the arrival of humans cause the coincidental extinction of large mammals in North America?