Level 1 - Absolute Beginner
Scientists may have found a new dwarf planet. Its name is 2026 ED138. It is far away in our solar system.
A big telescope in Chile found it. The telescope is called Rubin. A scientist named Matthew Holman saw it on October 13.
A dwarf planet is a small world. It goes around the Sun. Pluto is a dwarf planet. We know five now. This one could be the sixth.
First, scientists must look at it again and again. Then they can say yes.
- planet
- a big round world that goes around a star
- dwarf planet
- a small round world that goes around the Sun
- telescope
- a tool to see things far away
- scientist
- a person who studies the world
- solar system
- the Sun and the worlds around it
- far
- a long way away
- sixth
- number 6 in a list
- Pluto
- a dwarf planet far from the Sun
Level 2 - Elementary
Astronomers have a new candidate for a dwarf planet. It is called 2026 ED138. Matthew Holman, a member of the team that runs the Rubin Observatory, spotted it on October 13, and the Minor Planet Center has now announced it.
The Rubin Observatory in Chile takes huge pictures of the sky night after night. This helps scientists find objects that move slowly far from the Sun.
Right now, the solar system has five officially recognized dwarf planets. If 2026 ED138 is confirmed, it will be the sixth.
Confirmation is not quick. Scientists must follow the object for a long time to measure its path, its size and its shape. Only then can they decide if it is a dwarf planet.
- astronomer
- a scientist who studies stars and planets
- candidate
- something that might be chosen or proved
- observatory
- a building with telescopes
- announce
- to tell the public officially
- recognized
- accepted as official
- confirmed
- proved to be true
- path
- the way an object moves
- shape
- the form of something
Level 3 - Intermediate
Astronomers are weighing a new candidate for the solar system's sixth recognized dwarf planet. The object, designated 2026 ED138, was spotted on October 13 by Matthew Holman, a member of the operations team of the Vera Rubin Observatory in Chile, and its existence was subsequently announced by the International Astronomical Union's Minor Planet Center.
The designation is provisional. To qualify, an object must orbit the Sun, be massive enough to have pulled itself into a rounded shape, and not have cleared its orbital neighborhood. Today only five bodies, including Pluto and Eris, hold that title.
Rubin's strength is repetition. The observatory scans the southern sky again and again with a camera of extraordinary size, so slow-moving bodies in the distant outer solar system show up as faint points that shift from night to night.
Before any recognition, researchers must gather more observations to pin down the object's orbit and measure its size. Candidates have previously lost their promise once follow up data showed they were smaller or less round than first thought.
- designated
- officially given a name or label
- provisional
- temporary until confirmed
- orbit
- the path of an object around a larger one
- massive
- having a large amount of matter
- neighborhood
- the area around something
- repetition
- doing something again and again
- faint
- very weak or hard to see
- follow up
- further action after a first step
Level 4 - Advanced
The roster of the solar system's dwarf planets could soon grow. A candidate designated 2026 ED138, picked out on October 13 by Matthew Holman of the Vera Rubin Observatory's operations team and publicized by the Minor Planet Center, would become the sixth if its credentials survive scrutiny.
That caveat is substantial. The International Astronomical Union's definition demands that a body circle the Sun, possess enough mass for self gravity to render it roughly spherical, and fall short of dominating its orbital zone. Five objects, among them Pluto and Eris, currently satisfy those criteria, and the path from provisional label to formal recognition is typically measured in years rather than weeks.
What makes the announcement noteworthy is the instrument behind it. Rubin's wide field camera revisits the southern sky relentlessly, which is precisely the cadence needed to tease out sluggish, dim bodies that creep across the background of stars at the edge of the planetary realm.
Astronomers will now compete for telescope time to refine its orbit and estimate its diameter. History counsels restraint: promising discoveries have occasionally been demoted as better data revealed lumpier or smaller bodies than early estimates implied.
- roster
- a list of members or items
- credentials
- qualities that show something is suited
- scrutiny
- careful and critical examination
- caveat
- a warning or condition
- spherical
- shaped like a ball
- cadence
- a regular rhythm or pace
- sluggish
- slow moving
- restraint
- careful self control
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