Euclid, which is primarily a dark-energy/cosmology mission, may have a microlensing component, consisting of perhaps four dedicated one-month campaigns aimed at the Galactic bulge. We show that such a program would yield excellent auxilliary science, including asteroseismology detections for about 100 000 giant stars, and detection of about 1000 Kuiper Belt Objects (KBOs), down to 2–2.5 mag below the observed break in the KBO luminosity function at I ∼ 26. For the 400 KBOs below the break, Euclid will measure accurate orbits, with fractional period errors . 2.5%.

Abstract
1. INTRODUCTION
2. EUCLID CHARACTERISTICS
3. ASTEROSEISMOLOGY
    3.1. Bright-Star Photometry
    3.2. Bright-Star Astrometry
    3.3. Analytic Error Estimates for Bright Euclid Stars
    3.4. Asteroseismic Simulations for Euclid
    3.5. Role of Euclid Parallaxes
4. KUIPER BELT OBJECTS
    4.1. Euclid IR Observations of KBOs
    4.2. Correction to Gould (2014) Formula:Number of Trials
    4.3. Euclid Optical Observations of KBOs
    4.4. Detections
    4.5. Orbital Precision
    4.6. Binaries
    4.7. Occultations
    4.8. Computational Challenges
    4.9. Comparison to the Deep HST Search
5. CONCLUSION
REFERENCES

• Dennis Stello(School of Physics, University of Sydney/Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University)
• Daniel Huber(School of Physics, University of Sydney/SETI Institute/Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University)
• Andrew Gould(Department of Astronomy Ohio State University) Corresponding author