Celery teaches Jet, Sean, Sydney and Mindy about the planets in our solar system; Sydney, Mindy, Sunspot and Sean help Jet cook for his parents.

Jet explains how his family found Earth; the kids turn a treehouse into their own observatory to view the nighttime sky.

The kids learn how the planets orbit the sun and rotate on their own axes at the same time; Jet gets surprising results when he attempts to grow a plant from his home planet.

The kids learn how Earth is the perfect distance from the sun; Jet, Sean and Sydney learn about solar power.

The kids do a re-enactment of the first moon landing. Jet gives a gift to Mindy, which allows her to defy gravity.

Beep is sad because her sister Boop is sick and can't move so the kids fly to Mars to figure out what is wrong; Jet and Sean help Sydney turn her chores into fun science games.

The kids join Celery and Carrot on a trip to Mars; and Jet builds a robot version of himself so that he can be in two places at once.

Mindy finds out there is more than one moon in the solar system; Sean and Sydney take Jet to meet Sean's mom at the Deep Space Array.

Jet and Sydney go away on a mission to Mars; Sean is surrounded by noise while trying to complete his science project.

The kids meet up with Uncle Zucchini and start to clean up their space neighborhood; Jet, Sydney, and Sean build paper airplanes.

The kids help get Boop over a ravine on Mars, and learn that satellites help scientists communicate with far away rovers; the kids learn about constellations.

The Propulsions try out a new dashboard operating system, which only serves to confuse them as their test drive to Mars goes horribly wrong.

Sunspot acts strange when Mindy, Jet, Sean and Sydney use a solar panel to try to improve energy efficiency; Sean is excited about NASA's Year in Space program.

Sydney, Sean and Mindy plan fun things for Jet's first Halloween, including carving jack-o'-lanterns, dressing up in costumes and going trick-or-treating; Carrot and Celery turn their garage into a haunted house.

Sunspot and the kids attempt to build the tallest tower on the moon; Sean and Sydney want to take Jet to the DSA Open House.

The kids make their own Valentine's; Sydney directs everyone in a backyard movie.

Mindy explores her special zone with her friends; a dig uncovers a special item linked to the wild west past.

Celery competes against her brother, Uncle Zucchini, in a race; Jet tests his first experimental time machine.

Jet proposes a song to calm Sean's nervousness about flying; the kids plan a surprise party for Jet.

Celery, Jet and Sunspot accidentally leave Carrot on the moon. / A loud thunderstorm jolts everyone awake.

Mindy has finally turned five and is super excited that she is now old enough to go to space. But she's planned a tea party in the backyard. The kids convince Mindy to move her tea party to the Moon! In her first trip to space ever, Mindy gets to board the Propulsion family saucer and experience space travel, rounding out their Moon tea party with a quick trip out to Pluto and back.

"Endless Summer": Jet is amazed to find out that the entire Earth doesn't have the same season at the same time. So he flies with Sydney and Sean from the northern hemisphere to the southern hemisphere to compare and experience holidays in winter and summer...all in one day! "Jet Shrinks the Kids": Mindy feels bad that she's the smallest kid in the group, so sympathetic Jet and friends use a shrink-ray and become her size. The plan goes awry, and Jet, Sean, Sydney, and Sunspot become the size of mice. Mindy has to follow intricate diagrams to reverse the shrink-ray!

"Mindy's Ice Rink": Mindy is impatient for winter, because she wants to ice skate. So Jet, Sean, Sydney, and Celery fly to Saturn's icy rings to gather ice from them and return to build a Saturn-ringed skating rink around Jet's house. "Measure for Measure": Jet, Sydney, Sean, Mindy, and Sunspot decide to make a scaled replica of the solar system using found items in their own neighborhood and in doing so learn that an Astronomical Unit is the distance from the Earth to the Sun.

"Mindy and Carrot Bake": While making a cake, Carrot and Mindy find they are one are short one ingredient, so they head to the store. But Carrot accidentally pushes a wrong button on the wagon's newly-updated control panel, and they take off into outer space! Using a diagram, methodical experimentation, and record keeping, Mindy and Carrot figure out how to properly fly the saucer back home, where they finally finish the cake. "Commander Cressida Begins": Mindy has a problem: now that she's been to space with the bigger kids, she realizes how much there is out there to see! How can she decide where to explore next? Sydney asks her mom, Dr. Skelley, who presents them with the very first edition of Commander Cressida comics! In reading the comic book, Mindy comes to appreciate that she, like Commander Cressida, can explore space "one adventure at a time."

"Mindy's Bedtime": Mindy has to go to bed when the Sun goes down, but she's having such a fun day with her friends. She asks Jet and the others to help her keep the Sun from going down. The older kids humor Mindy and try to help "slow down the Sun." All their efforts make Mindy so sleepy that she decides to go home and sleep. "Galileo, Galileo!": Sydney and Jet are having a hard time explaining to Mindy that the Sun doesn't move - the Earth is moving around the Sun, so the Sun seems to move. Then Sean comes over dressed as his science hero Galileo, getting ready to do a school report. Mindy asks "Galileo" to explain why the Sun seems to move, and Sean practices for his report by explaining how the planets move, in character as Galileo!

"Eye in the Sky": Sean is planning his first sleepout under the stars with his Space Scouts troop, but the weather is threatening and it looks like his sleepout will be rained out. The kids get help from Mitchell, building a weather observation station to make a weather prediction, and visit the DSA for further help by tracking the weather with satellites. "Total Eclipse Block Party": A total eclipse of the Sun is coming to Boxwood Terrace! The kids prepare a Total Eclipse song and dance to perform at the DSA, where the whole town is gathered for the event. Meanwhile, Sunspot attempts to explain the eclipse to all the local animals so they won't think it's night and sleep through it.

"Souped-Up Saucer": Celery has souped-up the family saucer, adding new features for the kids to use, including a robot arm. They test drive it with a trip to the Moon. "Pet Sounds": Jet takes care of Mitchell's dog Cody for the weekend, and attempts to teach him some new tricks.

"I Feel the Earth Move": When the kids experience an earthquake in Boxwood Terrace, Celery takes them up into space to study the Earth's plates and fault lines from above. "Zerk Visits Earth": Jet's overactive cousin Zerk comes to Earth for a visit, and the kids show him around the neighborhood.

"Asteroid Belt Space Race": The kids join Celery in a space race with Uncle Zucchini, Auntie Eggplant and Zerk. "Sydney 2": Sydney designs and builds a robot companion for Jet 2.

"Earth Wind & Flyer": Jet is fascinated by the effects of wind on his saucer. He and the kids study how wind works, ending with Sean going on a wild saucer ride. "Mini-Golf At The DSA": Jet is fascinated by Earthie golf, and Sean and Sydney try to teach him the rules. When the DSA builds a new mini-golf course, the kids team up against the grownups, and Jet gets to apply his new knowledge of force.

"Water, Water Everywhere": Celery takes the kids on a saucer tour all around the Earth to discover all the ways that water can be found. They visit Antarctica to look at the ice, and then compare that extreme to the icy surface of Jupiter's moon Europa. "Commander Cressida Story Contest": Sydney wants to enter a Commander Cressida story contest, but can't think up a good enough story. The other kids help, and they come up with a story about lassoing a comet to bring water to Venus, and then Mars.

"Try and Try Again": Jet's robot Jet 2 needs new wheels if he's going to be able to rove over the surface of Mars. Jet and the kids try a bunch of different wheels, without success. In the end, they borrow the wheels from Mitchell's scooter, so Jet 2 can successfully navigate on Mars. "Racing on Sunshine": The kids enter their karts in the big kid-kart derby, but this year they all have to design solar powered karts. Jet learns how solar panels work, and how batteries save up the energy so you can race even when clouds cover the Sun.

"You Can Call Me Albedo": It's evening at the cul-de-sac, and the kids are looking at two asteroids through Sean's telescope - one is light-colored and one is dark. Meanwhile, Mitchell's dog Cody seems to have run away because he doesn't like the black sweater Mitchell put on him. The kids learn about how, just like asteroids, some things are easier to see in the dark than others, like a white card is easier to see than Cody's black sweater. This amount of brightness is called 'albedo'. "The Tide is High": The kids go to their local beach to surf, but notice that the beach looks completely different from the last time they stood there. There's way more sand, and the ocean is far away! They decide to be detectives and study what has happened, and learn that the larger and smaller beach is caused by the tides - the rising and falling of the ocean.

Jet is impatient and uses Bortronian technology to grow a pumpkin. However, the pumpkin becomes enormous and is too big to carry to the local Pumpkin Contest. Jet and his friends need to figure out a way to get it to the contest in time. At the same time, Mindy is going trick-or-treating with her two BFFs: Lillian and Mitchell. Mindy and Lillian think that Halloween is magical. Mitchell, on the other hand, has different opinions. Mindy tries to convince him that it is.

"Freebird": Some snow geese start to invade Jet's backyard. Jet and the gang are confused at first, but eventually learn that they are using the backyard as a stopping place while they migrate. "Sean's Robotic Arm": Mindy the mary-sue knocks Sean's prized Neil Armstrong action figure out of his hands and it ends up falling into a narrow Crevasse. Sean is very sad because of this. Luckily, Jet, Sydney, Mindy, Mitchell, Sunspot, and Cody all help him out by constructing a robotic arm made out of various items that will get Neil out of the hole. Also, in this episode, Mindy hugs Mitchell.

"Ain't No Mars Mountain High Enough": Sunspot wants to join an elite society called the Space Summit Society, so he needs to climb Mt. Sharp, on Mars. The other kids accompany him on his quest to climb Mt. Sharp. At first, he rejects help from them, but he eventually learns the value of working together. "Treasure Map": Sean, Sydney, and Mindy are all going away, leaving Jet with Mitchell. Mitchell, inspired by Treasure Island, wants to dig for buried treasure in his backyard. Wanting to do something nice for Mitchell, Jet makes a treasure chest for Mitchell to find, and also makes a map, unbeknownst to Mitchell.

"Moon Face": Mindy thinks there's a face on the moon. The kids investigate to see what causes the 'face' on the moon. "Lone Star 2 - Rocket Kids!": In this sequel to season 1's "Lone Star", the kids design a foot rocket while Sydney tells them about how Lone Star engineered and built the first rockets.

"Astronaut Ellen Ochoa": When Astronaut Ellen Ochoa comes to visit the DSA and review an engineering project, she runs into the kids, who are running Sean's lemonade stand to raise money for a rocket to Mars. They end up hanging out with her before her DSA meeting. They solve an engineering problem together, which inspires Ellen to use the same solution with the engineering project at the DSA.

"Potatoes on Mars": Jet is fascinated by the Earthie potatoes that the kids have grown in the backyard garden. Now he wants to try to grow potatoes on Mars! They take several plants to Mars and try, but learn that potatoes need the right air, temperature, water, and even the right soil. "Bortron Leprechaun": Jet is fascinated by his first Earthie rainbow. He wants to know all about them! Sydney tells Jet about the mythical Leprechauns that keep a pot of gold at the end of the rainbow, and even though they explain that it's only a story, Jet insists on following the rainbow to its end and meeting a magical leprechaun.

"Who Messed Up the Treehouse?": The kids do a bunch of projects in the treehouse. Sean makes paper airplanes, Jet has a picnic with Sunspot, Sydney makes Commander Cressida comics, and Mindy makes a puppet show. However, they leave a lot of trash there. No one wants to take responsibility for it. They try to find other places to play, but they don't work out. In the end, they learn to share the responsibility and keep the treehouse clean. "Fact or Fiction": Mindy tells Jet that clouds are made out of cotton balls. Jet, of course, believes this, but Sean and Sydney don't. Mindy says she learned this from Lillian. Lillian later clarifies that she thinks clouds are made of cotton candy, which Jet and Mindy also end up believing, much to Sean and Sydney's annoyance. The kids go to Dr. Rafferty and Dr. Skelley, who teach them what clouds are really made of and how to find correct information.

"Moon Circus": It is Carrot's 250th birthday. The kids make a circus to celebrate. They tell Jet not to tell Carrot, but Carrot ends up finding out anyway. The kids can't do their stunts on Earth because of the high gravity, and Carrot strains his back while trying to do a famous flip of this. In the end, the decision is made to transfer the circus to the moon, where everyone can do their circus tricks due to the low gravity. "Every Day is Earth Day": Today is Earth Day. The kids are making posters to celebrate. The kids travel around the Earth to find out what makes Earth so special. Then they use a Bortronian hot air balloon to get to the local DSA Earth Day celebration. Mitchell performs a poem about Earth. Carrot mixes up "toaster" and "poster" and presents a toaster, much to Mr. Peterson's annoyance. The kids arrive in their hot air balloon, and Jet leads everyone in a big song about Earth.

"My Three Suns": The kids play shadow tag, but then the clouds cover the sun, making it so that they can't play shadow tag. Then, the kids learn about a planet with 3 suns, Proxima B. They are glad to live on a planet with just one sun. Meanwhile, Face 9000 tries to take up comedy. "Magnet, P.I.": Sean becomes a magician called the Great Seanzo and dazzles the other kids with magnet tricks.

"Sunspot's Sunspot": Sunspot is sick and acts weird. This is because of a big sunspot on the sun. He gets cured when he gets closer to the sunspot. "Our Sun is a Star!": Lillian has a sleepover with Mindy planned, but it's too cold to have a sleepover outside. The kids learn about stars.

"Mars Rock for Mom": On Mother's Day, Jet realizes that he left Jet 2 on Mars and he and his friends travel there to recover him. "Sean Has a Cold": Sean gets sick on the first windy day of Spring and misses out on kite flying with his friends.