There is one Comet Medal in each of Super Mario Galaxy 2’s 49 galaxies. Collect the medal and finish the mission safely, then verify it on the galaxy’s selection screen. Medal collection and star collection are separate checks.
Two flight-course medals
Wild Glide and Fleet Glide require all five comet-shaped gates in the same flight to open the medal enclosure near the finish. Missing one gate leaves the cage closed, even if you complete the flight itself.
World 1
Sky Station Galaxy
On the cylindrical grass planet, stay on the second moving stone platform as it travels around the surface. Ride it beyond the normal exit to collect the medal.
Full Sky Station Galaxy walkthrough
Yoshi Star Galaxy
Free Yoshi from the Magikoopa, then check the small hill to the left of the nearby fruit. Use Yoshi’s jump to reach the medal on top.
Full Yoshi Star Galaxy walkthrough
Spin-Dig Galaxy
Use the Spin Drill to cross between the two sides of Drill Zone Planet. Line up with the tall dirt column so drilling from its opposite end places Mario on the column holding the medal.
Full Spin-Dig Galaxy walkthrough
Fluffy Bluff Galaxy
On the shallow-water sphere with five Star Chips, keep Cloud Mario dry. Use clouds to reach the medal above the metal spike before leaving in the Launch Star.
Full Fluffy Bluff Galaxy walkthrough
Flip-Swap Galaxy
Search the fourth panel section with four sets of rolling Chomps. Cross to the medal between their routes, timing spins so a landing panel remains under Mario.
Full Flip-Swap Galaxy walkthrough
Rightside Down Galaxy
At the two Thwomps, use the walls between them to wall-jump up to the medal. Wait for a clear opening rather than jumping under a descending Thwomp.
Full Rightside Down Galaxy walkthrough
Bowser Jr.'s Fiery Flotilla
On the approach to the castle, climb above the Thwomp blocking the path. The medal floats directly overhead; ride the Thwomp and jump from its top.
Full Bowser Jr.'s Fiery Flotilla walkthrough
World 2
Puzzle Plank Galaxy
On Grinder Planet, inspect the light-brown starting section before the saws cut it apart. Collect the medal there before continuing to the later wooden platforms.
Full Puzzle Plank Galaxy walkthrough
Boulder Bowl Galaxy
Defeat the three Elite Octoombas to take the Rock Mushroom. Smash the large purple crystal on the starting planet with Rock Mario to release the medal inside.
Full Boulder Bowl Galaxy walkthrough
Cosmic Cove Galaxy
Before freezing the water in Twin Falls Hideaway, dive into the large swimming area. Enter the giant underwater shell to collect the medal.
Full Cosmic Cove Galaxy walkthrough
Hightail Falls Galaxy
Keep Dash Yoshi running up the slope with the moving platform. At the sharp left turn at the top, steer through the medal before continuing to the grapple flowers.
Full Hightail Falls Galaxy walkthrough
Honeybloom Galaxy
In the second flower-and-cloud section, look beside the Choppah near the vine. Fly into the small gap holding the medal, keeping clear of the rotor blades.
Full Honeybloom Galaxy walkthrough
Wild Glide Galaxy
Pass through all five comet-shaped gates in one flight. This opens the medal’s enclosure near the finish; steer through it before crossing the finish line.
Full Wild Glide Galaxy walkthrough
Bowser's Lava Lair
Find the second Thwomp and climb onto its back after it drops. Backflip and spin into the medal above it, or use the adjacent wall for extra height.
Full Bowser's Lava Lair walkthrough
World 3
Tall Trunk Galaxy
On Wood Drum Planet, take the Blimp Fruit near the checkpoint and logs. Float left from that fruit to collect the medal, then descend to resume the Star Chip route.
Full Tall Trunk Galaxy walkthrough
Cloudy Court Galaxy
At the castle-wall ending, the medal sits between the crushing walls beside another Cloud Flower. Ride a cloud upwards with the wind when the walls open.
Full Cloudy Court Galaxy walkthrough
Haunty Halls Galaxy
Follow the first mission’s disappearing-path section to its far end. Collect the medal before entering the pipe into the hidden halls, watching the moving path beneath it.
Full Haunty Halls Galaxy walkthrough
Freezy Flake Galaxy
Use the Fire Flower to clear the snow-block fortress behind the first Bowser snow statue. Search the gap among the snow blocks near the pipe to the lava section.
Full Freezy Flake Galaxy walkthrough
Rolling Masterpiece Galaxy
On the long wooden cylinder before the Homing Chomp arena, steer the Star Ball through the medal while the saws are cutting the course. Avoid waiting until the supporting wood disappears.
Full Rolling Masterpiece Galaxy walkthrough
Beat Block Galaxy
After the second path’s checkpoint, collect the medal on the connecting route before the final pyramid. Jump to the beat and use solid purple platforms to pause.
Full Beat Block Galaxy walkthrough
Bowser Jr.'s Fearsome Fleet
When the moving-platform route passes the airships, board the second ship with the Hammer Bro. Collect the medal on that ship before returning to the main route.
Full Bowser Jr.'s Fearsome Fleet walkthrough
World 4
Supermassive Galaxy
At the giant spinning coin near the beginning, look above the nearby gap. Long-jump through the medal, using the large platforms to line up the crossing.
Full Supermassive Galaxy walkthrough
Flipsville Galaxy
Use the starting room’s grates to move between its upper and lower sides. At the second grate on the returning upper route, backflip into the medal before taking the third grate onwards.
Full Flipsville Galaxy walkthrough
Starshine Beach Galaxy
Swim towards the floating buoy in the Silver Star mission. Leave Yoshi and dive into the small underwater cave beneath that area to collect the medal.
Full Starshine Beach Galaxy walkthrough
Chompworks Galaxy
At the starting planet’s upper section, the medal floats above the rolling Chomps. Wait for a gap in the stream, jump through the medal and return to safe ground.
Full Chompworks Galaxy walkthrough
Sweet Mystery Galaxy
Keep Bulb Yoshi lit after the first curved platform. Reveal the invisible branch on the right and follow it to the medal before the berry effect expires.
Full Sweet Mystery Galaxy walkthrough
Honeyhop Galaxy
After the floating flower lifts you, continue to the small grassy ledge on the main planet. Wall-jump up the narrow gap: the Silver Star is lower down, while the medal is above it.
Full Honeyhop Galaxy walkthrough
Bowser's Gravity Gauntlet
Just inside the castle, find the Brick Block near the checkpoint. Backflip onto it and jump into the medal overhead before following the changing-gravity route.
Full Bowser's Gravity Gauntlet walkthrough
World 5
Space Storm Galaxy
In Follow Me, Bob-omb, circle the cylindrical planet with electric fences. Long-jump into the medal near a fence while avoiding the moving electric barrier.
Full Space Storm Galaxy walkthrough
Slipsand Galaxy
Before the giant sand slide, cross the S-shaped sand stream patrolled by three Cluckbooms. Take the medal along that stream while moving against the current.
Full Slipsand Galaxy walkthrough
Shiverburn Galaxy
At the far end of Magma Slice Planet, check beside the Launch Star before leaving for the skating area. Cross the moving stone platforms promptly so they do not carry Mario into a lava wall.
Full Shiverburn Galaxy walkthrough
Boo Moon Galaxy
Ride the Snake Blocks through the sinking swamp. Near the Launch Star, collect the medal from the moving route before taking the launch; the starting platforms collapse behind you.
Full Boo Moon Galaxy walkthrough
Upside Dizzy Galaxy
In the section where gravity reverses periodically, look above the first moving platform. Use the active upward gravity to reach the medal without touching the electric boundary.
Full Upside Dizzy Galaxy walkthrough
Fleet Glide Galaxy
Fly through all five comet-shaped gates during the battlefield glide. The medal cage in the final section then opens. Steer through it while avoiding the last cannons and airships.
Full Fleet Glide Galaxy walkthrough
Bowser Jr.'s Boom Bunker
On the spinning-platform planet, reach the second ring of platforms. The medal is between two Space Mines. Use the Cloud Flower to stabilise the approach and avoid the mines.
Full Bowser Jr.'s Boom Bunker walkthrough
World 6
Melty Monster Galaxy
In The Magnificent Magma Sea, search the small asteroids near the last lava planet. Collect the medal on one of those rocks between the Magmaws’ passes, before breaking the normal star’s crystal.
Full Melty Monster Galaxy walkthrough
Clockwork Ruins Galaxy
On Rolling Drum Planet, check the first slope with huge rolling cogs. Use their recessed sections for shelter while reaching the medal, before continuing to the spike-and-wall-jump section.
Full Clockwork Ruins Galaxy walkthrough
Throwback Galaxy
Near the checkpoint on the fortress climb, look below the main path for a small balcony. Jump and spin onto it to collect the medal, then work back to the upper route.
Full Throwback Galaxy walkthrough
Battle Belt Galaxy
On the small brown planet with three Li’l Cinders, collect the medal over a lava pool. Clear a safe jumping line and grab it before taking the next pipe.
Full Battle Belt Galaxy walkthrough
Flash Black Galaxy
Use Blimp Yoshi in the first dark tower. Float towards the upper-left branch to collect the medal; the Launch Star is on the upper-right side.
Full Flash Black Galaxy walkthrough
Slimy Spring Galaxy
In the first underwater tunnel, take a Green Shell and search the left wall. Enter the side passage near the Snoodles to collect the medal, then return to the main tunnel.
Full Slimy Spring Galaxy walkthrough
Bowser's Galaxy Generator
Keep Yoshi through the Snake Block lava section. Near its end, use the Blimp Fruit to reach the medal while avoiding the Magmaargh. Collect it before continuing towards the final door.
Full Bowser's Galaxy Generator walkthrough
World S
Mario Squared Galaxy
Search the bottom-left of the Mario-shaped starting planet. Reach the medal over the shrinking tiles, keeping a route back to a solid Flipswitch Panel.
Full Mario Squared Galaxy walkthrough
Rolling Coaster Galaxy
At the junction, choose the right-hand Expert Path. Steer through the medal on the narrow rainbow route; the easier branch does not pass it.
Full Rolling Coaster Galaxy walkthrough
Twisty Trials Galaxy
Reach the later group of four angled rotating blocks. Collect the medal from the third block of that group, waiting for its surface to rotate into a usable landing angle.
Full Twisty Trials Galaxy walkthrough
Stone Cyclone Galaxy
Ride the circulating stone platforms to the long slabs that slide sharply left and right. Time a jump across those slabs to collect the medal without being pushed into the void.
Full Stone Cyclone Galaxy walkthrough
Boss Blitz Galaxy
At King Kaliente’s planet, walk around to the underside of the arena. The medal is there beside the Life Mushroom; take it before launching to the next boss.
Full Boss Blitz Galaxy walkthrough
Flip-Out Galaxy
After the late grating and wall-jump section, long-jump from the platform towards the medal. Jump back without spinning accidentally, because a spin retracts the platform you need.
Full Flip-Out Galaxy walkthrough
Grandmaster Galaxy
In The Ultimate Test, take the far-right detour among the final Hammer Bro platforms, near the torches. Collect this medal before attempting to unlock The Perfect Run.
Full Grandmaster Galaxy walkthrough
The forty-ninth medal
Grandmaster appears only after the first 240 stars. Its medal is therefore a late return to the medal checklist, not a missing collectible in an earlier world. Take it during The Ultimate Test and check the Banktoad requirement for The Perfect Run.