New images show just how much our world has changed

A number of missions in the works aim to seek out the potential for life on moons around Jupiter and Saturn.

Perseverance continues to check out Mars years before humans plan to arrive, and Heinz announced this week its first ketchup produced under Mars-like conditions -- evidence that we can maybe grow tomatoes on the red planet one day.

The excitement surrounding these other worlds often overshadows news about Earth, except for when we're worried about asteroids or space weather hitting us.

New perspectives on our "blue marble" shared this week are a stark reminder that this is the only home we have -- and it needs our help. The images show a changing world, already far different from what previous generations knew.

Once upon a planet

Here's looking at you, Earth.

The NASA Landsat 9 mission, which launched in September, has beamed back its first high-resolution images of our world. This satellite is the latest in a succession of missions that have provided snapshots of Earth since 1972.

Such continuous, long-term data is critical for scientists tracking the impacts of the climate crisis. These new photos show changing landscapes around the world, including parts of the United States, Australia and the Himalayas.

Meanwhile, the Environmental Photographer of the Year awards reveal haunting images that capture life as it strives to survive in shifting habitats, including a boy fighting forest fires in New Delhi and sheep searching for grass in a drought.

Curiosities

History is filled with unique hallmarks, but this one earns the bling.

Archaeologists in Israel have discovered a gold and purple amethyst ring at the site of the Byzantine era's largest known winery. And it's possible this ring was worn to prevent any of the less-pleasant aspects of drinking too much alcohol.

That's right, it's a hangover ring.

Amethyst has other associations, and it's not the only odd hangover cure we've abandoned over time.

Fantastic creatures

Cats are masters when it comes to finding and fitting into secret hiding places. If you've ever lost track of your feline friend and called her name, only to turn and find kitty right behind you, it's not mystical cat magic.

It turns out cats can track your "invisible presence" using only their ears (which is science, but frankly sounds like cat magic). Audio cues, like the voices of their owners, allow cats to keep mental tabs on their people at all times.

Cats participating in a recent study seemed surprised when audio recordings of their owners appeared to teleport from place to place.

This sound-based connection hints that cats are more complex than we thought -- something with which we're sure all cats would agree.

Wild kingdom

Giant murder hornets certainly live up to their name. They are known for killing honeybees, destroying their hives and taking the nest for their own.

But honeybees have a warning signal they use to alert others when they smell the approach of the marauding hornets.

You have to hear this chilling warning noise to believe it. The sound is similar to the "antipredator pipe" other animals use when they are afraid.

And the signal is just the beginning. It serves as a call to action to the other bees, which triggers their unique defensive mechanisms when under attack, including poop repellant.

Across the universe

If gravitational waves make you think of an ocean phenomenon in space, you're not wrong. Scientists detected a record-breaking "tsunami" of these ripples in space-time between November 2019 and March 2020.

The cosmic waves were largely created by pairs of merging black holes, but several were born of rare collisions between dense neutron stars and black holes. The ripples only reached the detectors on Earth after traveling across the universe for billions of years.

Gravitational waves can help scientists better understand the violent life cycle of stars and why they turn into black holes or neutron stars when they die.

Discoveries

Don't miss these intriguing finds:

-- This dinosaur's bones have been hanging out in a museum since 1978. Now, scientists say it's a previously unknown species.

-- A Ferris wheel-size asteroid may actually be a lost fragment of the moon.

-- Venomous sharks have been discovered in one of the largest cities in the world.

Like what you've read? Oh, but there's more. Sign up here to receive in your inbox the next edition of Wonder Theory, brought to you by CNN Space and Science writer Ashley Strickland, who finds wonder in planets beyond our solar system and discoveries from the ancient world.

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