ABANDONED. Two books I read in elementary school

[Neocarleen]

In the first one, there was a human colony on a planet that had really long days and nights (something like 30-40ish hours). The main character meets a young alien which is smaller and uses smells to communicate. There's also one part where it has to regenerate or sleep at the bottom of a river.

The next one is about a boy who goes to Egypt and runs into his identical twin. He also has some kind of medalian that allows his to see into the past. The climax involves them being chanced through a pyramid by a mummy who had tried to create an immortality potion, but was then trapped in a coffin.

If anybody knows what either of these books are, I would greatly appreciate it! ;)

[Mir]

Around what year did you read these?

This doesn't fit exactly, but Pamela Service's Reluctant God has a lot of elements (twins, time travel, medallion, Egypt, mummy) in common with the second book you describe.

[Neocarleen]

Early 2000s. I remember I read the second book around 2003, but even then it was a older, worn out copy. I think it was even the second of a series, but I never read anything before it.

It wasn't Reluctant God.

[Neocarleen]

The description sounds familiar, so it was probably Shatterworld, though I certainly don't remember it having such obvious religious undertones. Ah well...

Still stuck on the second book.

[HeavyReader]

Should we add Shatterworld to the group's bookshelf?

[bookel]

The second book is:

Return to the Tomb of Death by Alida E. Young
When Don Hunt's long-lost twin brother is kidnapped and hidden in the depths of a mummy's ancient tomb, Don returns to Egypt to fight an age-old curse and save his brother.
"There are encounters with a mummy and an ancient vizier. There is an ancient curse and there are medallions with mystical powers."

That is the sequel to:

Terror in the Tomb of Death by Alida E. Young
At first Don thinks the ancient curse sounds ridiculous. But now his parents are missing and Don has been warned to leave Egypt. Maybe there's something to the curse after all. He can't leave yet. He has to find his parents, But Don's investigations only lead him to....

[Lobstergirl, au gratin]

Neocarleen has left the group so I'm moving this to Abandoned.