The 42nd Period | STEM Education Hub

🎯 Deliverable — Pick a Format

A pitch for your invented planet, backed by its detection data sheet.

🎤 Slide Pitch

5–8 slides, presented in 2–3 minutes, as if you were asking a telescope committee for observing time.

🪧 Poster or Brochure

A single poster or folded brochure — part travel ad, part science report — with the data sheet front and center.

🛠️ Build Your Data Sheet

Choose a star, then design your planet. The builder uses the same rules as Activities 6.1.1 and 6.1.2 to show the data a telescope would record — and flags anything that would hurt your case. Change your design until you can defend it.

Calm and long-lived — often called the habitability sweet spot.

Orbital distance (AU)Radius (Earth radii)Mass (Earth masses)

Habitable zone0.52 – 0.93 AUIn the habitable zone

Orbital period247 daysFrom Kepler's third law: P² = a³ ÷ M★

Transit depth0.022% (215 ppm)Big enough for Kepler/TESS-class photometry

Star's wobble0.22 m/sBelow current radial-velocity limits

Density5.74 g/cm³Rocky, like Earth

Tidal lockingUnlikelyClose-in planets tend to keep one face toward their star

Assumes a circular orbit seen edge-on (so the planet transits). Your pitch needs these numbers — copy them onto your data sheet and show the work for at least the zone edges, the transit depth, and the density.

📊 Sample Data Sheet — Earth, Seen From Afar

Here's what an alien astronomer would record for Earth. Your data sheet needs the same fields — for your own planet, not this one.

Sol d (Earth)

DATA SHEET · SAMPLE

IN ZONE

StarG-type · L 1 · M 1 · R 1 (Sun = 1)

Habitable zone0.95 – 1.70 AU

Distance · period1.00 AU · 365 days

Transit depth0.0084% (84 ppm)

Star's wobble0.09 m/s — below today's limits

Radius · mass · density1.0 R⊕ · 1.0 M⊕ · 5.5 g/cm³

Notice the catch: Earth transits, but its wobble is too small to measure with today's instruments. An honest pitch for an Earth twin would say so.

🧭 What Makes a Strong Pitch

Tie every claim to a number. Not "it's in the zone" but "at 0.70 AU, it sits between the 0.52 and 0.93 AU edges."
Use the whole checklist. Zone, rocky size, a calm star, and an atmosphere — skipping one is the first thing a reviewer will notice.
Say what you can't know yet. Atmosphere, magnetic field, water — name what would still have to line up.
Pick a star on purpose. Red dwarfs make planets easy to detect but bring flares and tidal locking. Sun-like stars are friendlier but make Earth-sized planets harder to find.
Check detectability. A perfect planet no telescope could confirm is a weaker pitch than a good one we could observe next year.

📋 Content Checklist

Every item below has to show up somewhere in your pitch — check them off as you go.

A name for your planet, and your chosen star type with its luminosity, mass, and radiusA detection data sheet: distance, period, transit depth, wobble, radius, mass, density, and zone edgesA habitability argument covering all four factors: zone, rocky size, star, and atmosphereAt least three things that would still have to line up (things we couldn't confirm yet)One skeptical reviewer's objection, and your responseA detection plan: which method(s) could confirm it, and whether today's instruments couldAt least one visual of your planet and its place in the habitable zone

📅 Day-by-Day Plan

Day 1

Design & Calculate

Choose your star and design your planet. Run it through the builder, adjust until you can defend every number, and copy your data sheet — with work shown for the zone edges, transit depth, and density.

Day 2

Build the Pitch

Build your slides or poster: the habitability argument, what would still have to line up, and your detection plan. Add a visual of your planet and its place in the habitable zone.

Day 3

Face the Reviewer & Submit

Pitch to a partner who plays a skeptical reviewer using the 6.1.2 checklist. Write down their toughest objection and your response, revise, then present or submit.

📊 Grading Rubric — 100 pts

A starting point — adjust weights to fit your class before assigning.

Category	Weight	Exemplary	Proficient	Developing	Incomplete
Data Consistency & Accuracy	30 pts	Every number on the data sheet is correct and consistent with the others — distance, period, transit depth, wobble, radius, mass, density, and zone edges.	One value off or one inconsistency.	Several values wrong or contradicting each other (e.g. a rocky density for a 4-Earth-radius planet).	Data sheet missing.
Habitability Argument	25 pts	Uses all four checklist factors — zone, rocky size, star, atmosphere — each tied to a specific number or choice.	Covers most factors; one is thin.	Relies almost only on being in the habitable zone.	No argument.
What Has to Line Up	15 pts	Names at least three things we couldn't yet confirm, and gives a strong response to a skeptical reviewer's objection.	Names three unknowns, but the reviewer response is thin.	Claims the planet is definitely habitable, or ignores obvious weaknesses.	Missing.
Detection Plan	15 pts	Explains which method(s) could confirm the planet and whether its signals are big enough for today's instruments.	Names a method but doesn't check detectability.	Detection plan vague or wrong.	Missing.
Pitch & Design	15 pts	Clear, persuasive, and visually polished; data is easy to find; delivered confidently.	Clear with minor rough spots.	Hard to follow or data buried.	Not submitted.

← Back to Project 6.1.3 🔬 Review 6.1.1 →🔬 Review 6.1.2 →

🔭 Project 6.1.3 · Unit 6 of 6 · Single Semester