What a great story!

Exploring the universe, and thinking about how it's all connected is an amazing activity for anybody. It must feel magical to a 7-year old!

I think you're right to be a bit skeptical about the authenticity of those cards. Nestle is a food brand, but I suppose it's possible they distributed those cards in their products at some point, and your friend picked them up from a resell site, like Ebay. Applause, Inc. seems to be a company that has been defunct since 2004, and a quick search didn't make it obvious that they dealt in this kind of product. And, as you mentioned, spaceresearch.com isn't active anymore.

Still, that hardly matters in the context of this story; indeed, there is debris from space falling to Earth all the time! I would want to take the stuff out and examine it, too!

Perhaps you could just look at it through a microscope while it's still in there.

I recall an experiment I saw demonstrating how you can find some trace metals that almost certainly include material from space from a place like your rooftop (might be from Steve Spangler). I didn't spend time finding the clip, but here's a similar step-by-step experiment generated by pi.ai in case you want to try something like this. In my opinion, it might be even cooler than the "star" stuff in those cards:

Materials needed:

• A plastic sheet or tarp
• A clean, dry container (could be a plastic baggie)
• A strong magnet
• A plastic wrapper (e.g. plastic bag or plastic wrap)
• A small, clean paintbrush
• Water

Procedure:

1. Choose a location on your rooftop or gutter where debris and dust tend to collect, ideally away from sources of local pollution.
2. Place the plastic sheet or tarp under the selected area to catch any particles that may fall during the experiment.
3. Use the clean paintbrush to gently sweep the debris and dust from the chosen area into the container.

Method 1 (with magnet inside the container):

1. Place the magnet inside a plastic bag and gently shake it inside the container. This will help separate the magnetic particles (which are more likely to be of extraterrestrial origin) from the non-magnetic debris.
2. Carefully remove the magnet from the container, keeping it inside the plastic bag. The magnetic particles should be stuck to the magnet.

Method 2 (with magnet outside the container):

1. Add water to the container, allowing it to mix with the collected debris.
2. Allow the mixture to settle for at least 10 minutes. This will give the magnetic particles time to sink to the bottom.
3. With the container placed on a flat surface, gently move the magnet around the bottom of the container from the outside. This will attract and gather the magnetic particles into a clump.
4. Slowly pour out the water, being careful not to disturb the clump of magnetic particles. You can now observe or collect these particles for further analysis.

Using either method, you can separate magnetic particles from collected debris, potentially including those of extraterrestrial origin.

I think the idea of the experiment is that, except for certain kinds of airborne pollution, magnetic materials found in a place like the gutters around the roof of a building are likely to have fallen through the atmosphere from space. When you collect it, you're sure to have some space material there. Cool!

The other thing this makes me think of is Neil deGrasse Tyson's quote:

The atoms of our bodies are traceable to stars that manufactured them in their cores and exploded these enriched ingredients across our galaxy, billions of years ago. For this reason, we are biologically connected to every other living thing in the world. We are chemically connected to all molecules on Earth. And we are atomically connected to all atoms in the universe. We are not figuratively, but literally stardust.