A RenderFlex overflowed by 8.3 pixels on the right.

final baseTextStyle = const TextStyle(
    fontFamily: 'Poppins'
);
final regularTextStyle = baseTextStyle.copyWith(
    color: const Color(0xffb6b2df),
    fontSize: 9.0,
    fontWeight: FontWeight.w400
);
final subHeaderTextStyle = regularTextStyle.copyWith(
    fontSize: 12.0
);
final headerTextStyle = baseTextStyle.copyWith(
    color: Colors.white,
    fontSize: 18.0,
    fontWeight: FontWeight.w600
);

Widget _planetValue({String value, String image}) {
  return new Row(
      children: <Widget>[
        new Image.asset(image, height: 12.0),
        new Container(width: 8.0),
        new Text(planet.gravity, style: regularTextStyle),
      ]
  );
}


final planetCardContent = new Container(
  margin: new EdgeInsets.fromLTRB(76.0, 16.0, 16.0, 16.0),
  constraints: new BoxConstraints.expand(),
  child: new Column(
    crossAxisAlignment: CrossAxisAlignment.start,
    children: <Widget>[
      new Container(height: 4.0),
      new Text(planet.name, style: headerTextStyle),
      new Container(height: 10.0),
      new Text(planet.location, style: subHeaderTextStyle),
      new Container(
          margin: new EdgeInsets.symmetric(vertical: 8.0),
          height: 2.0,
          width: 18.0,
          color: new Color(0xff00c6ff)
      ),
      new Row(
        children: <Widget>[
          new Expanded(
              child: _planetValue(
                  value: planet.distance,
                  image: 'assets/img/ic_distance.png')

          ),
          new Expanded(
              child: _planetValue(
                  value: planet.gravity,
                  image: 'assets/img/ic_gravity.png')
          )
        ],
      ),
    ],
  ),
);


final planetCard = new Container(
  child: planetCardContent,
  height: 124.0,
  margin: new EdgeInsets.only(left: 46.0),
  decoration: new BoxDecoration(
    color: new Color(0xFF333366),
    shape: BoxShape.rectangle,
    borderRadius: new BorderRadius.circular(8.0),
    boxShadow: <BoxShadow>[
      new BoxShadow(
        color: Colors.black12,
        blurRadius: 10.0,
        offset: new Offset(0.0, 10.0),
      ),
    ],
  ),
);


return new Container(
    height: 120.0,
    margin: const EdgeInsets.symmetric(
      vertical: 16.0,
      horizontal: 24.0,
    ),
    child: new Stack(
      children: <Widget>[
        planetCard,
        planetThumbnail,
      ],
    )
);