# Wide-Orbit Exoplanet Demographics

## TL;DR

This paper reviews current and future methods for detecting wide-orbit exoplanets, emphasizing the importance of filling the knowledge gap to better understand planet formation and habitability.

## Contribution

It provides a comprehensive overview of detection techniques for wide-orbit exoplanets and discusses prospects and challenges for combined analyses across methods.

## Key findings

- Current detection methods include microlensing, radial velocities, Gaia astrometry, and direct imaging.
- Future missions like WFIRST will enhance wide-orbit planet detection.
- Joint analyses of multiple methods face significant obstacles.

## Abstract

The Kepler, K2 and TESS transit surveys are revolutionizing our understanding of planets orbiting close to their host stars and our understanding of exoplanet systems in general, but there remains a gap in our understanding of wide-orbit planets. This gap in our understanding must be filled if we are to understand planet formation and how it affects exoplanet habitability. We summarize current and planned exoplanet detection programs using a variety of methods: microlensing (including WFIRST), radial velocities, Gaia astrometry, and direct imaging. Finally, we discuss the prospects for joint analyses using results from multiple methods and obstacles that could hinder such analyses. We endorse the findings and recommendations published in the 2018 National Academy report on Exoplanet Science Strategy. This white paper extends and complements the material presented therein.