@MyCindy My son is now in college, but he attended RMP the summer after 9th grade. We are local, and it is possible that they are more likely to take local kids early, since they won’t stay in the dorms.
They now also have a 4-week program that they may try to direct younger students into. That is new since he attended RMP.
Having only had one year of HS classes may limit the projects they decide a student is ready for. My son was hoping to work in a particular physics lab, but he hadn’t yet taken calculus, so they gave him a CS project that was further down on his list. It worked out fine, and he ended up working in the lab of the physics professor he’d wanted to work with in 10th-12th grade. Doing research early during HS helped open up other opportunities later.
I found his old writing sample and resume on my computer. The writing sample is an essay that he wrote for https://www.astronomycamp.org/ for that same summer. Since he was accepted to both, he wasn’t able to attend Astronomy Camp. It was basically a 4-page science fiction piece that started “The following are selected log entries from the spaceship Starvoyage, on its 1000 year voyage to the star system of Gliese 667C, 22.7 light years away.” (Memories, so cute!)
Admission may have gotten more selective; I don’t know. This was 4 years ago.
His stats back then were:
4.0 UW/4.8 W, class rank 1 (didn’t stay that way).
5 in AP CS in 8th grade
In 9th he was taking AP Physics B (the old combo of Physics 1&2) and doubling up on Alg II/Trig and Precalc.
He was also in a HS engineering program, so had learned some machining and CAD at that point.
He took dual-enrollment intro biology the summer before 9th.
No PSAT/SAT/ACT scores at that point (but he mentioned CTY scores, which were high).
Lists of programming languages, CAD/etc tools, operating systems
His resume at that point still mentioned a CA State Science Fair award from 8th grade and county-level AMC 8 awards. ECs back then included teaching a C++ class to junior high students, along with 3 other CS teaching/mentoring activities. One small research activity at that point and some minor journalism.